Need Help with simple array program!
Hi, I have just recently started how to use arrays[] in Java and I'm a bit confused and need help designing a program.
What this program does, it reads in a range of letters specified by the user. The user then enters the letters (a, b or c) and stores these characters into an array, which the array's length is equal to the input range the user would enter at the start of the program. The program is then meant to find how many times (a,b and c) appears in the array and the Index it first appears at, then prints these results.
Here is my Code for the program, hopefully this would make sense of what my program is suppose to do.
import B102.*;
class Letters
static int GetSize()
int size = 0;
boolean err = true;
while(err == true)
Screen.out.println("How Many Letters would you like to read in?");
size = Keybd.in.readInt();
err = Keybd.in.fail();
Keybd.in.clearError();
if(size <= 0)
err = true;
Screen.out.println("Invalid Input");
return(size);
static char[] ReadInput(int size)
char input;
char[] letter = new char[size];
for(int start = 1; start <= size; start++)
System.out.println("Please enter a letter (a, b or c) ("+size+" max), enter # to stop:");
input = Keybd.in.readChar();
while((input != 'a') && (input != 'b') && (input != 'c') && (input != '#'))
Screen.out.println("Invalid Input");
System.out.println("Please enter a letter (a, b or c) ("+size+" max, enter # to stop:");
input = Keybd.in.readChar();
while(input == '#')
start == size;
break;
for(int i = 0; i < letter.length; i++)
letter[i] = input;
return(letter);
static int CountA(char[] letter)
int acount = 0;
for(int i = 0; i < letter.length; i++)
if(letter[i] == 'a')
acount++;
return(acount);
static int CountB(char[] letter)
int bcount = 0;
for(int i = 0; i < letter.length; i++)
if(letter[i] == 'b')
bcount++;
return(bcount);
static int CountC(char[] letter)
int ccount = 0;
for(int i = 0; i < letter.length; i++)
if(letter[i] == 'c')
ccount++;
return(ccount);
static int SearchA(char[] letter)
int ia;
for(ia = 0; ia < letter.length; ia++)
if(letter[ia] == 'a')
return(ia);
return(ia);
static int SearchB(char[] letter)
int ib;
for(ib = 0; ib < letter.length; ib++)
if(letter[ib] == 'b')
return(ib);
return(ib);
static int SearchC(char[] letter)
int ic;
for(ic = 0; ic < letter.length; ic++)
if(letter[ic] == 'c')
return(ic);
return(ic);
static void PrintResult(char[] letter, int acount, int bcount, int ccount, int ia, int ib, int ic)
if(ia <= 1)
System.out.println("There are "+acount+" a's found, first appearing at index "+ia);
else
System.out.println("There are no a's found");
if(ib <= 1)
System.out.println("There are "+bcount+" b's found, first appearing at index "+ib);
else
System.out.println("There are no b's found");
if(ic <= 1)
System.out.println("There are "+ccount+" c's found, first appearing at index "+ic);
else
System.out.println("There are no c's found");
return;
public static void main(String args[])
int size;
char[] letter;
int acount;
int bcount;
int ccount;
int ia;
int ib;
int ic;
size = GetSize();
letter = ReadInput(size);
acount = CountA(letter);
bcount = CountB(letter);
ccount = CountC(letter);
ia = SearchA(letter);
ib = SearchB(letter);
ic = SearchC(letter);
PrintResult(letter, acount, bcount, ccount, ia, ib, ic);
return;
} Some errors i get with my program are:
When reading in the letters to store into the array, I get the last letter I entered placed into the entire array. Also I believe my code to find the Index is incorrect.
Example Testing: How many letters would you like to read? 3
Enter letter (a, b or c) (# to quit): a
Enter letter (a, b or c) (# to quit): b
Enter letter (a, b or c) (# to quit): c
It prints "There are no a's'" (there should be 1 a at index 0)
"There are no b's" (there should be 1 b at index 1)
and "There are 3 c's, first appearing at index 0" ( there should be 1 c at index 2)
The last thing is that my code for when the user enters "#" that the input of letters would stop and the program would then continue over to the counting and searching part for the letters, my I believe is correct but I get the same problem as stated above where the program takes the character "#" and stores it into the entire array.
Example Testing:How many letters would you like to read? 3
Enter letter (a, b or c) (# to quit): a
Enter letter (a, b or c) (# to quit): #
It prints "There are no a's'" (should have been 1 a at index 0)
"There are no b's"
and "There are no c's"
Can someone please help me??? or does anyone have a program simular to this they have done and would'nt mind showing me how it works?
Thanks
lou87.
Without thinking too much...something like this
for(int start = 0; start < size; start++) {
System.out.println("Please enter a letter (a, b or c) ("+size+" max), enter # to stop:");
input = Keybd.in.readChar();
while((input != 'a') && (input != 'b') && (input != 'c') && (input != '#')) {
Screen.out.println("Invalid Input");
System.out.println("Please enter a letter (a, b or c) ("+size+" max, enter # to stop:");
input = Keybd.in.readChar();
if(input == '#') {
break;
letter[start] = input;
}you dont even need to do start = size; coz with the break you go out of the for loop.
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JFrame frm = new JFrame("Address List");
AddressList panel = new AddressList();
frm.getContentPane().add(panel,"Center");
frm.setSize(700,350);
frm.setVisible(true);
panel.ListDisplay();
public void actionPerformed(ActionEvent e)
String cmd;
cmd = e.getActionCommand();
if(cmd.equals("Add"))
txt1.setText("");
txt2.setText("");
txt3.setText("");
else if(cmd.equals("Save"))
mdl.addElement(txt1.getText());
list.setModel(mdl);
try
RandomAccessFile rand = new RandomAccessFile(fob,"rw");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
LineNumberReader line = new LineNumberReader(br);
if(fob.exists())
rand.seek(fob.length());
rand.writeBytes("* " + txt1.getText());
rand.writeBytes("\r\n" + "# " + txt2.getText());
rand.writeBytes("\r\n" + "# " + txt3.getText() + "\r\n");
else
System.out.println("No such file..");
txt1.setText("");
txt2.setText("");
txt3.setText("");
catch(IOException a)
System.out.println(a.getMessage());
else if(cmd.equals("Cancel"))
txt1.setText("");
txt2.setText("");
txt3.setText("");
else if(cmd.equals("Close"))
System.exit(0);
class ListInfo implements ListSelectionListener
public void valueChanged(ListSelectionEvent e)
ListSelectionModel lsm = (ListSelectionModel)e.getSource();
int minIndex = lsm.getMinSelectionIndex();
int maxIndex = lsm.getMaxSelectionIndex();
try //*this one should display the info of the person whenever i click the person's name at the list box via textbox.. but i cant seem to get it right since it always display the info of the first person inputed.. i tried to get the program to display them whenever it reads lines with * on them....
File fob = new File("Address3.txt");
RandomAccessFile rand = new RandomAccessFile(fob,"rw");
BufferedReader br = new BufferedReader(new FileReader("Address3.txt"));
LineNumberReader line = new LineNumberReader(br);
if(fob.exists())
for(int i = minIndex; i<=maxIndex; i++)
if(lsm.isSelectedIndex(i))
while((name = rand.readLine()) != null)
chars = name.toCharArray();
if(chars[0] == '#')
continue;
if(chars[0] == '*')
txt1.setText(rand.readLine());
txt2.setText(rand.readLine());
txt3.setText(rand.readLine());
else
System.out.println("No such file..");
catch(IOException a)
System.out.println(a.getMessage());
}the only problem now is about how it should display the right info about the person whenever i click its name on the list.. something about file reading or something, i just cant figure it out.
and also about how to make it scroll once it exceeds the list.. i cant make it work, maybe something about wrong declaration..
thanks in advance..
Edited by: syder on Mar 14, 2008 2:26 AMLike said before, do one thing at a time. At startup, something like:
//put all the content in a list
ArrayList<String> lines = new ArrayList<String>();
while(String line=rand.readLine()!=null) {
lines.add(line);
}If you follow the good advice to create a class to encapsulate the entries, you could populate a list of such entries like this:
static final int ENTRY_SIZE = 3;//you have 3 fields now, better to have a constant if that changes
ArrayList<Entry> entries = new ArrayList<Entry>();
for(int i=0; i<lines.size(); i+=ENTRY_SIZE) {
Entry entry = new Entry(lines.get(i), lines.get(i+1), lines.get(i+2);
entries.add(newEntry);
}You could also do both of the above in one run, but I think you will understand better what's happening if you do one thing at a time.
If you don't want to put the entries in an encapsulating class, you can still access this without looping:
int listStartIdx = <desired_entry_index>*ENTRY_SIZE;
String att1 = lines.get(listStartIdx).substring(1);
String att2 = lines.get(listStartIdx+1).substring(1);
String att3 = lines.get(listStartIdx+2).substring(1); -
Need help with a rudimentary program
I'm sort of new at this so i need help with a few things... I'm making a program to compile wages and i need answers with three things: a.) what are the error messages im getting meaning? b.) How can i calculate the state tax as 2% of my gross pay with the first $200 excluded and c.) how can i calculate the local tax as a flat $10 with $2 deducted for each dependant. any help is appreciated
Here is what i have so far:
public class WagesAsign1
public static void main(String[] args)
int depend=4;
double hrsWork=40;
double payRate=15;
double grossPay;
grossPay=payRate*hrsWork;
double statePaid;
double stateTax=2.0;
statePaid=grossPay*(stateTax/100);
double localPaid;
double localTax=10.0;
localPaid=grossPay*(localTax/100);
double fedPaid;
double fedTax=10.0;
double taxIncome;
fedPaid=taxIncome*(fedTax/100);
taxIncome=grossPay-(statePaid+localPaid);
double takeHome;
System.out.println("Assignment 1 Matt Foraker\n");
System.out.println("Hours worked="+hrsWork+" Pay rate $"+payRate+" per/hour dependants: "+depend);
System.out.println("Gross Pay $"+grossPay+"\nState tax paid $"+statePaid+"\nLocal tax paid $"+localPaid+"\nFederal tax paid $"+fedPaid);
System.out.println("You take home a total of $"+takeHome);
and these are the error messages so far:
WagesAsign1.java:23: variable taxIncome might not have been initialized
fedPaid=taxIncome*(fedTax/100);
^
WagesAsign1.java:29: variable takeHome might not have been initialized
System.out.println("You take home a total of $"+takeHome);
^edit: figured it out... please delete post
Message was edited by:
afroryan58 -
Hello guys need help with reverse array
Need help reversing an array, i think my code is correct but it still does not work, so im thinking it might be something else i do not see.
so far the input for the array is
6, 25 , 10 , 5
and output is still the same
6 , 25 , 10 , 5
not sure what is going on.
public class Purse
// max possible # of coins in a purse
private static final int MAX = 10;
private int contents[];
private int count; // count # of coins stored in contents[]
* Constructor for objects of class Purse
public Purse()
contents = new int[MAX];
count = 0;
* Adds a coin to the end of a purse
* @param coinType type of coin to add
public void addCoin(int coinType)
contents[count] = coinType;
count = count + 1;
* Generates a String that holds the contents of a purse
* @return the contents of the purse, nicely formatted
public String toString()
if (count == 0)
return "()";
StringBuffer s = new StringBuffer("(");
int i = 0;
for (i = 0; i < count - 1; ++i)
s.append(contents[i] + ", "); // values neatly separated by commas
s.append(contents[i] + ")");
return s.toString();
* Calculates the value of a purse
* @return value of the purse in cents
public int value()
int sum = 0; // starts sum at zero
for( int e : contents) // sets all to e
sum = sum + e; //finds sum of array
return sum; //retur
* Reverses the order of coins in a purse and returns it
public void reverse()
int countA = 0;
int x = 0;
int y = countA - 1; // 5 - 1 = 4
for (int i = contents.length - 1; i >=0 ; i--) // 4, 3 , 2, 1, 0
countA++; // count = 5
while ( x < y)
int temp = contents[x];
contents[x] = contents [y];
contents [y] = temp;
y = y- 1; // 4 , 3 , 2, 1 , 0
x = x + 1 ; // 0 , 1, 2 , 3 , 4
}ok so i went ahead and followed what you said
public void reverse()
int a = 0;
int b = contents.length - 1;
while (b > a)
int temp = contents[a];
contents[a] = contents;
contents [b] = temp;
a++;
b--;
}and its outputting { 0, 0, 0, 0}
im thinking this is because the main array is has 10 elements with only 4 in use so this is a partial array.
Example
the array is { 6, 25, 10, 5, 0, 0, 0, 0, 0, 0,}
after the swap
{0, 0 , 0 , 0, 0 , 0 , 5 , 10 , 25, 6}
i need it to be just
{ 5, 10, 25, 6}
so it is swapping the begining and end but only with zeroes the thing is i need to reverse the array without the zeroes -
Need Help With Simple ABAP Code
Hello,
I'm loading data from a DSO (ZDTBMAJ) to an Infocube (ZCBRAD06). I need help with ABAP code to some of the logic in Start Routine. DSO has 2 fields: ZOCTDLINX & ZOCBRDMAJ.
1. Need to populate ZOCPRODCD & ZOCREFNUM fields in Infocube:
Logic:-
Lookup /BI0/PMATERIAL, if /BIC/ZOCBRDMAJ = /BIC/OIZOCBRDMAJ
then /BIC/ZOCPRODCD = ZOCPRODCD in Infocube
/BIC/ZOCREFNUM = ZOCREFNUM in Infocube
2. Need to populate 0G_CWWTER field in Infocube:
Logic:
Lookup /BIC/PZOCTDLINX, if /BIC/ZOCTDLINX = BIC/OIZOCTDLINX
then G_CWWTER = 0G_CWWTER in Infocube.
I would need to read single row at a time.
Thanks!I resolved it.
-
Need help with accessing the program.
I need help with accessing my adobe creative cloud on my windows 8.1 laptop. I have an account but do not have an app. I need this for my online classes. Please help!
Link for Download & Install & Setup & Activation may help
-Chat http://www.adobe.com/support/download-install/supportinfo/ -
Need help with spell checker program
Hi
I am writing a spell checker program and need help for a simple logic.I have "List" of correctly spelled words and a String array of wrong spelled words.How can I compare both and tell that for eg xyz word is not spelled correctly.BigDaddyLoveHandles wrote:
To learn more about Map, take the collection tutorial: [http://java.sun.com/docs/books/tutorial/collections/index.html]
(Actually, to me it sounds like you have a Set of correctly spelled words and another Set of words which may or may not be correctly spelled, and you want the difference...)That is what it sounds like to me also, and that is easy.
JSG -
Beginner needs help with simple code.
I just statrted learnind java, and I need some help with this simple program. For some reason everytime I enter my Farenheit value, the Celsius conversion returns as 0.0. Would really appreciate the help. Thanks.
Here's the code:
public class TempConverter
public static void main(String[] args)
double F = Double.parseDouble(args[0]);
System.out.println("Temperature in Farenheit is: " + F);
double C = 5 / 9;
C *= (F - 32);
System.out.println("Temperature in Celsius is: " + C);
}double C = 5 / 9This considers "5" and "9" to be integers and does an integer division, discarding the remainder. The result of that division is 0. Trydouble C = 5.0/9.0;
-
I need help with simple problems. im a student.
i'd like to be advanced with my studies so i will post questions.. i need help on how to answer. thank you.
1. create a java program that will evaluate if the value entered is a positive, negative, vowel, consonant and special characters.
im actually done with the positive and negative using if else statements.. i used an integer data type. now my question is how do conjoin the characters when i need to evaluate a vowel and a consonant. i cant use char either. please help. i dont know what to do yet.
2. create java program that will translate the input from numbers to words. e.g. input:123 output: one hundred twenty-three.
i have an idea to use a switch case statement. but i have no idea on how will i be able to do it. so if you guys can help me.. well then thankies..Welcome to the Sun forums. First, please note that you have posted in the wrong forum. This forum is for topics related to Sun's JavaHelp product. You should post your questions in the New to Java forum.
As part of your learning, you will have to develop the ability to select an approach to a problem, create a design that reflects that approach, and then implement the design with code that you create.
So, it's inappropriate for us to take the problem statement that you have been given and short-circuit your learning process by giving you the implemented problem solution. We can comment on the individual questions that you may have, and point out problems and errors that we see in the code that you develop.
As a hint, when you are stuck, forget about Java and programming. Just start with a sheet of paper and a pencil, and figure out how to layout the task on paper. The consider how to translate that to programming.
If you have problems, post short example code that shows the problem, and explain your question clearly. We can't read minds.
Make sure you post code correctly so that it's not mangled by the forum software, and so that formatting is maintained. Select your typed or pasted code block and press the CODE button above the typing area. -
I can't see how to calculate the lowest hours, highest hours, and average hours worked.
These three values should be outputted each on a seperate line.
I just can't figure this out.
Any help please.
This program will show the employees
hours. It will have one
class.It will use an array to keep
track of the number of hours the employee
has worked with the output to the monitor
of the employees highest, lowest, and the
average of all hours entered. */
import java.util.*;
import java.text.DecimalFormat;
/*** Import Decimal Formating hours to format hours average. ***/
public class cs219Arrays
public static void main(String[] args)
Scanner scannerObject = new Scanner(System.in);
int[] employees ={20, 35, 40};
int employeesHighest = 40;
int employeesLowest = 20;
double employeesAverage = 35;
int[] firstEmployee = new int[1];
int[] secondEmployee = new int[2];
int[] thirdEmployee = new int[3];
System.out.println("This program will accept hours worked for 3 employees.");
System.out.println("Enter hours worked for employee #: ");
System.out.println(".\n");
employeesAverage = scannerObject.nextInt();
for(int count =20; count <= 40; count++)
DecimalFormat df = new DecimalFormat("0.00");
System.out.println("pay: " employeesAverage " lowest " employeesHighest " Highest hours " employeesLowest " Lowest hours "+df.format(employeesAverage));
System.out.print("\n");
employeesAverage++;
}/* end of body of first for loop */
for(int count =20; count <= 40; count++)
employeesAverage = employeesAverage + employeesHighest + employeesLowest;
DecimalFormat df = new DecimalFormat("0.00");
System.out.println("pay: $" employeesAverage " lowest " employeesHighest " Highest hours $" +df.format(employeesAverage));
System.out.print("\n");
employeesAverage++;
}/* end of body of second for loop */
for(int count =20; count <= 40; count++)
employeesAverage = employeesAverage + employeesHighest + employeesLowest;
DecimalFormat df = new DecimalFormat("0.00");
System.out.println("pay: $" employeesAverage " lowest " employeesHighest " Highest hours $" +df.format(employeesAverage));
System.out.print("\n");
employeesAverage++;
}/* end of body of third for loop */
System.out.println("\n");
DecimalFormat twoDigits = new DecimalFormat("0.00");
/*** Create new DecimalFormat object named twoDigits ***/
/*Displays number of hours, employees hours and average hours.*/
System.out.println("You entered " + employeesAverage + " number of hours.");
System.out.println("Your number of hours are " + twoDigits.format(employeesAverage));
System.out.println("\n\n");
} /*End of method for data.*/
{ /*Main method.*/
} /*End of main method.*/
} /*End of class cs219Arrays.*/Want help?
Use the code formatting tags for starters. http://forum.java.sun.com/help.jspa?sec=formatting
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