Better switch statement

Hi, with all the changes coming to Java, I'm curious
why not enhance
the switch statement, allowing the cases to test for
ranges, like it's done in basic.
Doesn't something like the following
switch(x) {
case 1 to 7: // do smth
case 8 to 12: // do smth else
look rather nice?
What do the wise people think?The tiger (1.5) release will address this with a construct for decisions based on ranges of values. Why sketchy, i believe it goes something like this
if ((x >=1) && (x <= 7))
doSomething();
else if ((x >= 8) && (x <= 12))
doSomethingElse();

Similar Messages

Enum class not supported for switch() statement in 12.4 beta?

Hi fellow 12.4 beta testers,
It would appear "enum class" isn't supported for switch() statements in the 12.4 beta. This compiles fine under clang and g++. Will this be fixed for the final release? This currently causes compile errors for us, since __cplusplus >= 201103L evaluates to true, so our code uses "enum class" instead of plain "enum". It looks like the C++11 standard says it should be supported:
   Switching on enum class in C++ 0x - Stack Overflow
Many thanks,
Jonathan.
$ cat test.cpp
#include <iostream>
enum class Ternary { KnownFalse = 0, KnownTrue = 1, Unknown = 2 };
int main( void )
   Ternary foo;
   switch ( foo ) {
      case Ternary::KnownTrue:
      case Ternary::KnownFalse:
      case Ternary::Unknown:
         std::cout << "Success\n";
$ clang++ -std=c++11 test.cpp
$ g++ -std=c++11 test.cpp
$ /opt/SolarisStudio12.4-beta_mar14-solaris-x86/bin/CC -std=c++11 test.cpp
"test.cpp", line 8: Error: Cannot use Ternary to initialize integral type.
"test.cpp", line 8: Error: Switch selection expression must be of an integral type.
"test.cpp", line 9: Error: An integer constant expression is required for a case label.
"test.cpp", line 10: Error: An integer constant expression is required for a case label.
"test.cpp", line 11: Error: An integer constant expression is required for a case label.
5 Error(s) detected.

Thanks for reporting this problem! I have filed bug 18499900.
BTW, according to the C++11 standard, the code is actually not valid. Section 6.4.2, switch statement, says an implicit conversion to an integral type is required, which is not the case for for a scoped enum (one using the "class enum" syntax). This limitation was raised in the C++ Committee as an issue to be fixed, and the C++14 standard makes the code valid.
As a workaround, or to make the code conform to C++11, you can add casts to int for the enum variable and the enumerators.
Message was edited by: Steve_Clamage

Switch statement for AS3 - Flash CS3

Hey guys, I currently have a code of a switch statement for as1- as2.
This is it:
switch (int(Math.random() * 20))
    case 0:
        hint = "The total amount of confusion in this world remains constant. It just gets shifted around.";
        break;
    case 1:
        hint = "If you experience poor performance, adjust the quality settings in your preference menu option.";
        break;
    case 2:
        hint = "Anticipation of death is better than death itself.";
        break;
    case 3:
        hint = "At the core of all well-founded belief lies belief that is unfounded.";
        break;
    case 4:
        hint = "The problem with instant gratification is that it takes too long.";
        break;
    case 5:
        hint = "Never let your schooling interfere with your education.";
        break;
    case 6:
        hint = "Beware of geeks bearing gifs.";
        break;
    case 7:
        hint = "Collaboration is essential: It allows you to blame someone else.";
        break;
    case 8:
        hint = "Read my MIPs - no new VAXes.";
        break;
    case 9:
        hint = "Where is the sea, said the fish, as they swam through it.";
        break;
    case 10:
        hint = "You can safely blame any bugs on Aoedipus, who is too busy grinding battlegrounds to do QA on her own work.";
        break;
    case 11:
        hint = "Anything worth doing is worth overdoing.";
        break;
    case 12:
        hint = "There is more to life than increasing its speed.";
        break;
    case 13:
        hint = "Don\'t worry, this will take about as long as the time it takes to play a 2v2 match with 4 ret pallies.";
        break;
    case 14:
        hint = "There is nothing worse than the brilliant image of a fuzzy concept.";
        break;
    case 15:
        hint = "If you are not part of the solution, you are part of the precipitate.";
        break;
    case 16:
        hint = "Two wrongs don\'t make a right, but three lefts do.";
        break;
    case 17:
        hint = "The heresy of today is the logic of tomorrow.";
        break;
    case 18:
        hint = "It\'s not that life is so short, it\'s just that you\'re dead a really long time.";
        break;
    case 19:
        hint = "Those who love sausage, the law, and holy canon should never watch any of them being made.";
        break;
    case 20:
        hint = "What if there were no hypothetical questions?";
        break;
} // End of switch
hint = "HINT: " + hint;
This code is for a dynamic tet with the var 'hint' (No ' ' )
But in as3 there is no var and I am having trouble converting it to AS3 coding, can someone show me the correct conversion of the code to make it work with AS3. I will make the instance name 'hint'.
Thank you ahead of time.

In addition to what other guys said, if you still want to use switch it should be:
switch (Math.round(Math.random() * 20)) - this will cover all the possible integers.
Nevertheless, I believe using switch in this case is not as efficient and scalable as using, say, array.
1. array index access is faster than switch.
2. if you need to make additions, you will need to make additions in switch while with array you just need to add/subtract member
3. if you will need to switch to a more dynamic model (say, getting hints from xml) - it will not be possible with switch
4. you may need a greater degree of randmization (Math.random is not as random as one may think) in which case resorting/reordering array is much simpler and faster.
So, I suggest you switch to the following code:
var hints:Array = [];
hints[0] = "Anticipation of death is better than death itself.";
hints[1] = "Anything worth doing is worth overdoing.";
hints[2] = "At the core of all well-founded belief lies belief that is unfounded.";
hints[3] = "Beware of geeks bearing gifs.";
hints[4] = "Collaboration is essential: It allows you to blame someone else.";
hints[5] = "Don\'t worry, this will take about as long as the time it takes to play a 2v2 match with 4 ret pallies.";
hints[6] = "If you are not part of the solution, you are part of the precipitate.";
hints[7] = "If you experience poor performance, adjust the quality settings in your preference menu option.";
hints[8] = "It\'s not that life is so short, it\'s just that you\'re dead a really long time.";
hints[9] = "Never let your schooling interfere with your education.";
hints[10] = "Read my MIPs - no new VAXes.";
hints[11] = "The heresy of today is the logic of tomorrow.";
hints[12] = "The problem with instant gratification is that it takes too long.";
hints[13] = "The total amount of confusion in this world remains constant. It just gets shifted around.";
hints[14] = "There is more to life than increasing its speed.";
hints[15] = "There is nothing worse than the brilliant image of a fuzzy concept.";
hints[16] = "Those who love sausage, the law, and holy canon should never watch any of them being made.";
hints[17] = "Two wrongs don\'t make a right, but three lefts do.";
hints[18] = "What if there were no hypothetical questions?";
hints[19] = "Where is the sea, said the fish, as they swam through it.";
hints[20] = "You can safely blame any bugs on Aoedipus, who is too busy grinding battlegrounds to do QA on her own work.";
hint = hints[int(Math.random() * hints.length)];
// OR
hint = hints[Math.round(Math.random() * (hints.length - 1))];

Static Methods & Switch Statement

Need help with a switch statement and static methods. My program offers the user a menu to choose what they want to practice.
I want to use a switch statement to process the selection. Selecting 1, 2 or 3 causes the program to go to one of the following static methods:
addition()
subtraction
multiplication()
import javax.swing.JOptionPane; // Needed for JOptionPane
import java.text.DecimalFormat; // Needed for DecimalFormat
public class MathsFinal {
    static boolean exit = false;
    static int totalAnswersAsked = 0;
    public static void main(String[] args)
        int userChoice;
        int correctAnswers = 0;
        do{
            //custom button text
            do{
                boolean exitAsking = true;
                String userChoiceString = JOptionPane.showInputDialog (null,
                        "1. Practice addition\n"
                        + "2. Practice subtraction\n"
                        + "3. Practice multiplication\n"
                        + "4. Quit the program\n"
                        + "\n"
                        + "Enter your choice",
                        "Enter your choice",
                        JOptionPane.QUESTION_MESSAGE);
                int userAnswer, genNumOne, genNumTwo;
                if(userChoiceString == null || userChoiceString.equals("4") )
                    { //closed it
                    exit = true;
                }else if(userChoiceString.equals("1"))
                    { //addition
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(9,0);
                    userAnswer = genNumOne + genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "plus");
                }else if(userChoiceString.equals("2"))
                    { //subtraction
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(genNumOne,0);
                    userAnswer = genNumOne - genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "minus");
                }else if(userChoiceString.equals("3"))
                    { //multiplication
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(9,0);
                    userAnswer = genNumOne * genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "times");
                }else
                    { //user didn't enter a number
                    JOptionPane.showMessageDialog(null,
                            "Please enter a number between 1 and 4",
                            "Wrong entry",
                            JOptionPane.ERROR_MESSAGE);
                    exitAsking = false;
            while(!exit);
        while(!exit);
        //create a DecimalFormat object for percentages.
        DecimalFormat userPercent = new DecimalFormat("#0%");
        //show results using information icon
        JOptionPane.showMessageDialog(null,
                "You got " + (userPercent.format(((double)correctAnswers / (double)totalAnswersAsked))) + " right!!",
                "Thank you for playing",
                JOptionPane.INFORMATION_MESSAGE);
        //ends the program
        System.exit(0);
    public static int getRandomNumber(int large, int small)
        return (int)((large - small) * Math.random()) + small;
    public static int display(int genNumOne, int genNumTwo, int userAnswer, String operation)
        String selectAddition = JOptionPane.showInputDialog("What is" + " " + genNumOne + " " + operation + " " + genNumTwo + "?");
        if(selectAddition == null) { //pressed close
            exit = true;
            return 0;
         else if(userAnswer == Integer.parseInt(selectAddition))
          { //answer correct
            totalAnswersAsked++;
            //show results using information icon
            JOptionPane.showMessageDialog(null,
                    "Very good!",
                    "Well done",
                    JOptionPane.INFORMATION_MESSAGE);
            return 1;
         else if(userAnswer != Integer.parseInt(selectAddition))
          { // incorrect answer
            totalAnswersAsked++;
            JOptionPane.showMessageDialog(null,
                    "Sorry that was incorrect. Better luck next time",
                    "Bad luck",
                    JOptionPane.INFORMATION_MESSAGE);
            return 0;
        return 0;
}

hi,
switch statement to process the selection. Selecting 1, 2 or 3
import javax.swing.JOptionPane; // Needed for JOptionPane
import java.text.DecimalFormat; // Needed for DecimalFormat
public class MathsFinal {
    static boolean exit = false;
    static int totalAnswersAsked = 0;
    public static void main(String[] args)
        int userChoice;
        int correctAnswers = 0;
       int userChoiceString=4;
        do{
            //custom button text
                boolean exitAsking = true;
                userChoiceString = Integer.parseInt(JOptionPane.showInputDialog (null,
                        "1. Practice addition\n"
                        + "2. Practice subtraction\n"
                        + "3. Practice multiplication\n"
                        + "4. Quit the program\n"
                        + "\n"
                        + "Enter your choice",
                        "Enter your choice",
                        JOptionPane.QUESTION_MESSAGE));
                int userAnswer, genNumOne, genNumTwo;
               switch (userChoiceString)
               case 1:
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(9,0);
                    userAnswer = genNumOne + genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "plus");
                         break;
                    case 2:
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(genNumOne,0);
                    userAnswer = genNumOne - genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "minus");
                          break;
                    case 3:
                    genNumOne = getRandomNumber(9,0);
                    genNumTwo = getRandomNumber(9,0);
                    userAnswer = genNumOne * genNumTwo;
                    correctAnswers += display(genNumOne, genNumTwo, userAnswer, "times");
                         break;
                    case 4: break;
                 default :
                    JOptionPane.showMessageDialog(null,
                            "Please enter a number between 1 and 4",
                            "Wrong entry",
                            JOptionPane.ERROR_MESSAGE);
                    exitAsking = false;
            } while(userChoiceString != 4);
        //create a DecimalFormat object for percentages.
        DecimalFormat userPercent = new DecimalFormat("#0%");
        //show results using information icon
        JOptionPane.showMessageDialog(null,
                "You got " + (userPercent.format(((double)correctAnswers / (double)totalAnswersAsked))) + " right!!",
                "Thank you for playing",
                JOptionPane.INFORMATION_MESSAGE);
        //ends the program
        System.exit(0);
    public static int getRandomNumber(int large, int small)
        return (int)((large - small) * Math.random()) + small;
    public static int display(int genNumOne, int genNumTwo, int userAnswer, String operation)
        String selectAddition = JOptionPane.showInputDialog("What is" + " " + genNumOne + " " + operation + " " + genNumTwo + "?");
        if(selectAddition == null) { //pressed close
            exit = true;
            return 0;
         else if(userAnswer == Integer.parseInt(selectAddition))
          { //answer correct
            totalAnswersAsked++;
            //show results using information icon
            JOptionPane.showMessageDialog(null,
                    "Very good!",
                    "Well done",
                    JOptionPane.INFORMATION_MESSAGE);
            return 1;
         else if(userAnswer != Integer.parseInt(selectAddition))
          { // incorrect answer
            totalAnswersAsked++;
            JOptionPane.showMessageDialog(null,
                    "Sorry that was incorrect. Better luck next time",
                    "Bad luck",
                    JOptionPane.INFORMATION_MESSAGE);
            return 0;
        return 0;

Help with Switch statements using Enums?

Hello, i need help with writing switch statements involving enums. Researched a lot but still cant find desired answer so going to ask here. Ok i'll cut story short.
Im writing a calculator program. The main problem is writing code for controlling the engine of calculator which sequences of sum actions.
I have enum class on itself. Atm i think thats ok. I have another class - the engine which does the work.
I planned to have a switch statement which takes in parameter of a string n. This string n is received from the user interface when users press a button say; "1 + 2 = " which each time n should be "1", "+", "2" and "=" respectively.
My algorithm would be as follows checking if its a operator(+) a case carry out adding etc.. each case producing its own task. ( I know i can do it with many simple if..else but that is bad programming technique hence im not going down that route) So here the problem arises - i cant get the switch to successfully complete its task... How about look at my code to understand it better.
I have posted below all the relevant code i got so far, not including the swing codes because they are not needed here...
ValidOperators v;
public Calculator_Engine(ValidOperators v){
          stack = new Stack(20);
          //The creation of the stack...
          this.v = v;
public void main_Engine(String n){
     ValidOperators v = ValidOperators.numbers;
                *vo = vo.valueOf(n);*
     switch(v){
     case Add: add(); break;
     case Sub: sub(); break;
     case Mul: Mul(); break;
     case Div: Div(); break;
     case Eq:sum = stack.sPop(); System.out.println("Sum= " + sum);
     default: double number = Integer.parseInt(n);
                   numberPressed(number);
                   break;
                  //default meaning its number so pass it to a method to do a job
public enum ValidOperators {
     Add("+"), Sub("-"), Mul("X"), Div("/"),
     Eq("="), Numbers("?"); }
     Notes*
It gives out error: "No enum const class ValidOperators.+" when i press button +.
It has nothing to do with listeners as it highlighted the error is coming from the line:switch(v){
I think i know where the problem is.. the line "vo = vo.valueOf(n);"
This line gets the string and store the enum as that value instead of Add, Sub etc... So how would i solve the problem?
But.. I dont know how to fix it. ANy help would be good
Need more info please ask!
Thanks in advance.

demo:
import java.util.*;
public class EnumExample {
    enum E {
        STAR("*"), HASH("#");
        private String symbol;
        private static Map<String, E> map = new HashMap<String, E>();
        static {
            put(STAR);
            put(HASH);
        public String getSymbol() {
            return symbol;
        private E(String symbol) {
            this.symbol = symbol;
        private static void put(E e) {
            map.put(e.getSymbol(), e);
        public static E parse(String symbol) {
            return map.get(symbol);
    public static void main(String[] args) {
        System.out.println(E.valueOf("STAR")); //succeeds
        System.out.println(E.parse("*")); //succeeds
        System.out.println(E.parse("STAR")); //fails: null
        System.out.println(E.valueOf("*")); //fails: IllegalArgumentException
}

BUG - Switch statement & compiler

I am overriding AccordionHeader. In the set Data method I
have a switch statement. I dont think the location of the statement
is relevant, but included for completeness. (MenuGroup is my own
class and not relevant)
If you have the following code Flex 3 \ FB 3 (both beta 3)
override public function set data(value:Object):void
var menuGroup:MenuGroup = value as MenuGroup;
// examine the groupType to determine if we need \ want to
change the style setting
// on this particular header
switch(menuGroup.groupType)
super.data = value;
The compiler will fail with an 'An internal build error has
occurred' error.
Put in a default case statement such as
case default:
break;
and all is well.
regards BOb

Thanks for reporting. You can track the bug here
https://bugs.adobe.com/jira/browse/ASC-3113
Thanks,
Gaurav Jain
Flex SDK Team

Best way to write a fall-through switch statement?

I am trying to write the equivalent of a C-style
switch statement. The attached VI has 2 ways of
accomplishing this. Is there a better way? What are
the pros/cons of the two ways shown in the VI?
Attachments:
switch_statement.vi ‏42 KB

I have no better way of doing this, but I'll give you my opinion as to the
readability and the maintainability.
Readability:
I find option 2 more readable, the entire code is laid out and easy to
see without cycling through cases. It is pretty easy to see what it does
and how it works. Option 1 requires a little more thinking to follow the
logic, but is not undecipherable.
Maintainability:
I would think that option 1 is much more maintainable. Simply add
another case to the case structure and you're ready to go. No rewiring, no
need to clear out more room on the diagram. Seems easy to me. Option 2 is
going to require a little more work, and if room is already scarce on the
diagram, adding another case structure may make wiring more
difficult.
Overall:
I'm not sure I see where I would incorporate this in my code right now,
but if the need arose, I would probably do something like Option 1.
My thoughts
Spencer Anderson
"Jabberwocky" wrote in message
news:[email protected]..
> That does mimic my string example, but it doesn't solve the general
> situation. The switch in C is exactly like LabVIEW's Case Structure,
> but with one interesting property: you can set it up so that whichever
> case executes first, all cases after that will also execute. This is
> frequently useful when you have several values that need various
> amounts of work done and those work quantities are subsets of each
> other. The LV case structure only executes one frame of the structure.
> It would be pretty tricky, given the nature of dataflow, for NI to
> build a structure that can "fall through" the way C's switch can.
> That's why I was designing groups of structures that have th
is
> behavior. The two I showed in my original post are the only ones I
> have been able to come up with thus far.

Switch statement doubts

Hi guys...
in the switch statement can i leave the "default: " blank without having any statement to excute ...is that ok?
.<code>switch (expression) {
case cond1: code_block_1;
case cond2: code_block_2;
case condn: code_block_n;
{color:#ff0000}default: {color}
}</code>
I don't need a else else like state ment here, but i need to specify the "default:" otherwise i'm getting a warning to add default statement ,
that;s the reason that i'm asing whether i can leave this default blank?
Thanks in advance

dear folk,
you will be knowing how to run a java application. please write the main program put your Code (switch) in the main method and test it yourself thats the better way to understand it

Beginner question regarding switch statements with arrays....

Doing a little project for my beginner's object oriented programming course. I've written the following code, but the switch statement won't recognize my array values....I'm required to use a switch statement in my program, which will count various character types in an external file....any insight is appreciated.
import java.io.*;
public class MyProg
public static BufferedReader inFile;
public static void main(String[] args)
    throws IOException, StringIndexOutOfBoundsException
    String line;
    inFile = new BufferedReader(new FileReader("TME5Part1.dat3"));
      char UpperCase[]= {'A','B','C','D','E','F','G','H','I','J','K','L','M',
                                      'N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
      char LowerCase[]=     {'a','b','c','d','e','f','g','h','i','j','k','l','m',
                                      'n','o','p','q','r','s','t','u','v','w','x','y','z'};
      char Digit[]= {'0','1','2','3','4','5','6','7','8','9'};
      char EndMark[]= {'!','.','?'};
      char MidMark[]= {',',':',';'};
    char symbol;
    int upperCaseCt = 0;
    int lowerCaseCt = 0;
    int digitCt = 0;
    int endMarkCt = 0;
    int midMarkCt = 0;
      int spaceCt = 0;
      int otherCharCt = 0;
    line = inFile.readLine();          //read first line (priming read)
    while (line != null)               // Loop until end of data (empty line)
      for (int count = 0; count < line.length(); count++) // Loop until end of line
        symbol = line.charAt(count);
            for (int i=0; i<=25;i++)
                    char uppercase=UpperCase;               //get array values for i
                    char lowercase=LowerCase[i];
                    if (i<=9) {char digit=Digit[i];}
                    if (i<=2) {     char endmark=EndMark[i];
                                        char midmark=MidMark[i];
                    switch(symbol)
                              case uppercase : upperCaseCt++;
                                        break;
                              case lowercase : lowerCaseCt++;
                                             break;
                              case digit          : digitCt++;
                                             break;
                              case endmark     : endMarkCt++;
                                             break;
                              case midmark     : midMarkCt++;
                                             break;
                              case ' '          : spaceCt++;
                                             break;
                              default          : otherCharCt++;
                                             break;
          line = inFile.readLine();
     System.out.println("Number of uppercase letters = "+upperCaseCt);
     System.out.println("Number of lowercase letters = "+lowerCaseCt);
     System.out.println("Nubmer of digits = "+digitCt);
     System.out.println("Number of end punctuation marks = "+endMarkCt);
     System.out.println("Number of mid punctuation marks = "+midMarkCt);
     System.out.println("Number of spaces = "+spaceCt);
     System.out.println("Number of other characters = "+otherCharCt);
I was trying to do it this way rather than "case 'A':
case 'B':
case 'Z:" for each type of 'symbol'.
Unfortunately, the switch statement is required or this would be easier with arrays and for loops...I'm not sure if my code is even possible. Thanks in advance =)
Edited by: RiTarDid

RiTarDid wrote:
For sure it is the most straightforward way, but my curiosity is getting the better of me....I will most likely submit the program with the longer (value-by-value) switch method, as I haven't found anyone who can tell me how to properly reference an array value in a 'case'.Well, you can do this (basically):
switch(some_array[some_index]) {
    case 'a': blahblah
    case 'z': blahblah
}What you can't do is this:
switch(some_scalar_value) {
case a_whole_array: blahblah
case a_whole_another_array: blahblah
}Because the latter isn't what "case" means.
If you want to do something like the latter, use if/else statements. Here's a dirty little industry secret: people seldom use switch/case. if/else is a lot more common.
Actually that dirty little secret isn't really particular dirty or particularly secret. It is, however, little.
I just recall a suggestion to use arrays for any group that is more than 10 values in size;Well...sort of...
You should use the expression of data that's appropriate for what the data is. If it's a collection of data of the same kind and an ordering, then an array or a java.util.List makes sense. If it's data that is of the same kind but no ordering and no duplicates are allowed, use a java.util.Set. (Etc. on this front.) If it's a collection of un-alike data, but which belongs in associated groups (e.g., a user's name, age, height, and whether s/he's married) then you should create a class that represents that logical grouping. Etc. If you have more than 10 individual data that can't be grouped or collected somehow, then chances are you need to rethink what's happening.
so I wanted to see if an array could be employed for comparisons with the 'switch' statement. The program is simple enough, I'm just trying to flex my problem-solving muscle in different ways. :)
thanks for replying, hope I can get a definite "yes, it can be done this way" or "no it can't" if there's anyone out there who knows.....The problem is that your example is contrived. So you can do a variety of things that fit into the contrivance, but they'd be weird things.
In practice, you'd want to use the character classification methods in Character, if you wanted to characterize a bunch of characters. Or maybe a regular expression. There's no need to keep an array of characters to match against if you want to determine whether a particular character is upper case. In fact, that's the wrong way of doing things, because Character.isUpperCase is more likely to tell whether any character (not just stuff that's also an element of ASCII) qualifies as upper case.

HELP -menu using a switch statement

Hello to all. I'm new to the Java world, but currently taking my first Java class online. Not sure if this is the right place, but I need some help. In short I need to write a program that gives the user a menu to chose from using a switch statement. The switch statement should include a while statement so the user can make more than one selection on the menu and provide an option to exit the program.
With in the program I am to give an output of all counting numbers (6 numbers per line).
Can anyone help me with this?? If I'm not asking the right question please let me know or point me in the direction that can help me out.
Thanks in advance.
Here is what I have so far:
import java.util.*;
public class DoWhileDemo
     public static void main(String[] args)
          int count, number;
          System.out.println("Enter a number");
          Scanner keyboard = new Scanner (System.in);
          number = keyboard.nextInt();
          count = number;
          do
               System.out.print(count +",");
               count++;
          }while (count <= 32);
          System.out.println();
          System.out.println("Buckle my shoe.");
}

Thanks for the reply. I will tk a look at the link that was provided. However, I have started working on the problem, but can't get the 6 numbers per line. I am trying to figure out the problem in parts. Right now I'm working on the numbers, then the menu, and so on.
Should I tk this approach or another?
Again, thanks for the reply.

How to convert switch statement into iif than else statement in SSRS

Hi All;
How do i convert switch statement into iif statement in ssrs
=
Switch(
Fields!createdonValue.Value = Now(), "Today",
Fields!createdonValue.Value = DateAdd("d",-1,Today()),"Yesterday",
Fields!createdonValue.Value >= FORMATDATETIME(DateAdd(DateInterval.Day, -6,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate) and
Fields!createdonValue.Value <= FORMATDATETIME(DateAdd(DateInterval.Day, -0,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate),"Last Week",
Fields!createdonValue.Value >= FORMATDATETIME(DateAdd(DateInterval.Day, -13,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate) and
Fields!createdonValue.Value <= FORMATDATETIME(DateAdd(DateInterval.Day, -0,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate),"Last Fortnight",
Fields!createdonValue.Value >= DateValue(DateAdd("M",-1,DateAdd("D",-(Day(Now)-1),Now))) and
Fields!createdonValue.Value <= DateValue(DateAdd("D",-1,DateAdd("D",-(Day(Now)-1),Now))),"Last Month",
Fields!createdonValue.Value >= DateSerial(Year(Now()), 1, 1) and
Fields!createdonValue.Value <= DateSerial(Year(Now()), 12, 31),"Year to Date"
Any help much appreciated
Thanks
Pradnya07

Not sure why you want to se IIF as Switch is more compact
Anyways it will look like this
=IIf(
Fields!createdonValue.Value = Now(), "Today",IIf(
Fields!createdonValue.Value = DateAdd("d",-1,Today()),"Yesterday",Iif(
Fields!createdonValue.Value >= FORMATDATETIME(DateAdd(DateInterval.Day, -6,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate) and
Fields!createdonValue.Value <= FORMATDATETIME(DateAdd(DateInterval.Day, -0,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate),"Last Week",IIf(
Fields!createdonValue.Value >= FORMATDATETIME(DateAdd(DateInterval.Day, -13,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate) and
Fields!createdonValue.Value <= FORMATDATETIME(DateAdd(DateInterval.Day, -0,DateAdd(DateInterval.Day, 1-Weekday(today),Today)),DATEFORMAT.ShortDate),"Last Fortnight",IIf(
Fields!createdonValue.Value >= DateValue(DateAdd("M",-1,DateAdd("D",-(Day(Now)-1),Now))) and
Fields!createdonValue.Value <= DateValue(DateAdd("D",-1,DateAdd("D",-(Day(Now)-1),Now))),"Last Month",IIf(
Fields!createdonValue.Value >= DateSerial(Year(Now()), 1, 1) and
Fields!createdonValue.Value <= DateSerial(Year(Now()), 12, 31),"Year to Date")))))
Please Mark This As Answer if it helps to solve the issue Visakh ---------------------------- http://visakhm.blogspot.com/ https://www.facebook.com/VmBlogs

Use of boolean variables in BPEL switch statements

I have a workflow with a single boolean input parameter:
<element name="input" type="boolean"/>
I wish to use a switch statement within the workflow, based on the value of that boolean parameter.
When I use the following XPath expression:
bpws:getVariableData("input","payload","/tns:BooleanRequest/tns:input")
I get the correct functionality, although I get the following BPEL compiler warning:
" [bpelc] [Warning ORABPEL-10078]: return value of this expression may not be a boolean
[bpelc] [Description]: in line 35 of "C:\eclipse\workspace\Boolean\Boolean.bpel", xpath expression "bpws:getVariableData("input","payload","/tns:BooleanRequest/tns:input")" used in <switch> may not return boolean type value, the xpath engine would automatically try to convert the return value to boolean..
[bpelc] [Potential fix]: Please use one of the built-in boolean functions from xpath http://www.w3.org/TR/xpath#section-Boolean-Functions to convert the return value to boolean.."
However, the boolean functions referenced do not appear to be relevant to a variable which is already of a boolean type. If I attempt to use the boolean() function in my XPath expression, I get rid of the compiler error, but the workflow now does not work as required.
How can I get rid of the compiler warning and still get the required functionality, and/or am I doing the wrong thing?
I am currently running on JBoss, with BPEL release 2.1.2 [build #1226].
Thanks for any help or ideas.

Hi Marlon,
Thanks for that - I guess we have to accept the vagaries of XPath and the absence of type-checking for variables.
I hadn't fully understood until I started investigating that I can assign ANY string to variable of type xsd:boolean, which has been the cause of some of the confusion for me - whether that value is then considered true or false depends on how you write your test condition.
I tried with your condition, and it didn't seem to work (evaluated to true if the variable data was the string "true()", but otherwise it seemed to always evaluate to false.
I also tried the following:
condition="bpws:getVariableData('booleanVariable')=true()"
but that evaluates to true for any string of length > 0.
The only one I can get to consistently work is:
condition="bpws:getVariableData('booleanVariable')=string(true())"
although that means that variable data of "TRUE" will evaluate to false (may well be the correct behaviour, depending on how you're setting the boolean variable in the first place).

Compiler error when useing switch statements in an inner class

I have defined several constants in a class and want to use this constans also in an inner class.
All the constants are defined as private static final int.
All works fine except when useing the switch statement in the inner class. I get the compiler error ""constant expression required". If I change the definition from private static final to protected static final it works, but why?
What's the difference?
Look at an example:
public class Switchtest
   private static final int AA = 0;
   protected static final int BB = 1;
   private static int i = 0;
   public Switchtest()
      i = 0; // <- OK
      switch(i)
         case AA: break; //<- OK, funny no problem
         case BB: break; //<- OK
         default: break;
private class InnerClass
      public InnerClass()
         i = 0; // <- OK: is accessible
         if (AA == i) // <- OK: AA is seen by the inner class; i is also accessible
            i = AA + 1;
         switch(i)
            case AA: break; // <- STRANGE?! Fail: Constant expression required
            case BB: break; // <- OK
            default: break;
}Thank's a lot for an explanation.

Just a though:
Maybe some subclass of Switchtest could decalare its own variable AA that is not final, but it can not declare its own BB because it is visible from the superclass. Therefore the compiler can not know for sure that AA is final.

Switch Statement again

I am new to Java and am trying to learn how to use and understand the nuances involved in using the Switch statment.
Yesterday, I received tremendous help, As a result, I am closer to understanding the switch statement and how it works.
My program is designed to use 5 different input boxes. These represent a total for quizzes, homework assignments, 2 midterms, and a final exam.
These are casted to double; then, they are added together and divided by five to obtain an average (the student's GPA). The GPA is then going to assigned a grade depending up the range in the If then statement.
I intend on using a message box to inform the user of the GPA and another followed by another message box to show them their grade.
I would like to incorporate the switch statement (so I can learn how to use it) to show them their grade.
I know the code needs tweaking but this is what I have so far:
import javax.swing.JOptionPane;
public class Switchgrade{
//declaration of class
public static void main(String args[])
//declaration of main
String midone; String midtwo; String quiz; String homework; //declares variables to hold the grades, quiz and homework scores
String last;
double one; //first midterm
double two; //second midterm
double three;double four; double five; //final, quiz and homework scores
double average; //GPA
char a; char b; char c; char d; char f;char grade;
midone = JOptionPane.showInputDialog("Please enter the first midterm"); //first score to add
one = Double.parseDouble(midone);
midtwo = JOptionPane.showInputDialog("please enter second midterm"); //second midterm to add
two = Double.parseDouble(midtwo);
last = JOptionPane.showInputDialog("please enter final exam score");//final exam score to add
three = Double.parseDouble(last);
quiz = JOptionPane.showInputDialog("please enter quiz score");//quiz score to add
four = Double.parseDouble(quiz);
homework= JOptionPane.showInputDialog("please enter homework score");//homework score to add
five = Double.parseDouble(homework);
average = (one + two+ three + four + five)/5; //average of all five scores
if(average >= 90)
grade = 'a';
else
if(average >= 80 )
grade = 'b';
switch (grade)
case a:
JOptionPane.showMessageDialog(null,"The total of all your scores is " + b+"\nYour final grade is an A");
break;
default:
JOptionPane.showMessageDialog(null,"Sorry, you received a grade of " + b + ". \nYou failed.");
break;
System.exit(0);
}//end of main
}//end of class
As you can see, I am only using two grades, just so I can learn to use it. However, when I go to compile this, I get this error message:
constant expression required: case a:, with the ^ under the a.
What does this error message me and how do I fix this.
Thanks in advance for your help.

case a:is trying to use a variable with the name "a" for the comparison. This is illegal in java
what you want is
case 'a':this will do a comparison against the char value 'a'

Switch Statement

I am new to Java and am trying to learn how to use and understand the nuances involved in using the Switch statment.
I am trying to write an application that will calculate grades for a student. I can use the If Then Else Control structure for this (which runs) but I would like to incorporate the Switch Statement in place of the multiple if then else structure. Here is the code that I have for the application:
import javax.swing.JOptionPane;
public class Switchgrades
public static void main(String args[])
String midone; String midtwo; String quiz; String homework;
String last;
double one; //first midterm
double two; //second midterm
double three;double four; double five; //final, quiz and homework scores
double average; //GPA
int a; int b; double c; double d; double f;int grade;
midone = JOptionPane.showInputDialog("Please enter the first midterm"); //first score to add
one = Double.parseDouble(midone);
midtwo = JOptionPane.showInputDialog("please enter second midterm"); //second midterm to add
two = Double.parseDouble(midtwo);
last = JOptionPane.showInputDialog("please enter final exam score");//final exam score to add
three = Double.parseDouble(last);
quiz = JOptionPane.showInputDialog("please enter quiz score");//quiz score to add
four = Double.parseDouble(quiz);
homework= JOptionPane.showInputDialog("please enter homework score");//homework score to add
five = Double.parseDouble(homework);
average = (one + two+ three + four + five)/5; //average of all five scores
switch (grade)
case a: //this is where I become confused and lost. I don't what I need to do to make it run.
{if(average >= 90)
b = Integer.parseInt(average);
JOptionPane.showMessageDialog(null,"The total of all your scores is " + b+"\nYour final grade is an A");}
/ I am just using one choice to make it run. When I can make it run, I plan on incorporating the other grades.
break;
<=====================================================================>
<=====================================================================>
//else --->this is part of the if that works in another program
// if(average >= 80 )
// JOptionPane.showMessageDialog(null,"The total of all your scores is " + average +"\nYour final grade is a B");
//else
//if(average >= 70 )
// JOptionPane.showMessageDialog(null,"The total of all your scores is " + average +"\nYour final grade is a C");
//else
//if(average >= 60 )
// JOptionPane.showMessageDialog(null,"The total of all your scores is " + average +"\nYour final grade is a D");
//else
//if(average <= 60 )
<=====================================================================>
<=====================================================================>
default:
JOptionPane.showMessageDialog(null,"Sorry, you received a grade of " + average + ". \nYou failed.");
System.exit(0);
As you can see, I already have all the if then else statements set up--between the <==>. The program runs with the If's but I can two error messages when I incorporate the Switch statement.
1) constant expression required.
I have case a and i guess it is not a constant. Again, I don't understand switch well enough to figure what I need to do to correct it.
2)"b = Integer.parseInt(average);" - cannot resolve the symbol--whatever that means. I have a "^" pointing at the period between Integer and parseInt.
Can anyone help explain what I have to do to make this program work using Switch.
I have not used Switch before and don't understand what I can use as opposed to what I must use for it to work.
Thanks for your help.

I don't really know how you want your program going, but here is what I think.
1) From the start of the switch statement, where do you assign the value for "grade"? If you write the switch statement like below, you meant something like, if(grade == 'a'){...}, right!? Then, where did you get the "grade" from?
switch (grade)
case a:
You may want declare variable "grade" as char and place if sentence like this before the switch.
if(average >= 90)
grade = 'a';
else if(average >= 70)
grade = 'b';
switch (grade)
case a:
System.out.print("Your grade: A");
break;
case b:
System.out.print("Your grade: A");
break;
Is that What you want???
2)The method, Integer.parseInt(), takes String as parameter? Did you override this method? The variable "average" was declare as double, so why don't you just cast it to int??

Better switch statement

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