How to use * / - + in a switch statement?

So I wrote a calculator program (im just learning Java).
As a beginner I used the (press 1 for +, press 2 for - etc) now I want to go back and actually parse the real symbils * / - + and use those...
I am using JOptionPane library for getting numbers and stuff.. (inputting them as String then converting to doubles)...
How do I go about the operator symbols though? I can grab as as string no problem.. but then what?
Ive been trying to figure out how to make a switch statement.. but case *: doesnt work.. it doesnt like the *. Cant convert that to an into or a double (at least I dont think you can?) or is switch statement a bad way to go in this case?
Any help would be appreciated. :)

endasil wrote:
I should mention that it's extremely easy to form a switch statement that wouldn't have a performance benefit, by making the options very sparse. Like this:
int i = 1000;
switch ( i ) {
case 1:
break;
case 1000:
break;
}Since this is not going to be implemented as a branch table (given the values are so sparse) it probably provides no benefit.
enums, on the other hand, will be extremely fast in a switch since their integer values (ordinals) are packed as tightly as possible, starting at 0, by the compiler.
I wonder how Strings will fare in this regard. I suppose if the compiler mods the hashCode, it can pack the possible values fairly tightly. Also, I presume that the cases will have to be compile-time constants.
But the weirdest part to me is that it'll be actually computing the hash code of Strings at compile time. At first I thought this was reasonable when I discovered that String.hashCode's result was specified by the JLS [http://java.sun.com/docs/books/jls/first_edition/html/javalang.doc11.html#14460]. However, following JLS 1, those sections have been removed. So where is the specification for Java libraries now? Is it simply the Javadoc (String#hashCode()'s Javadoc does specify the actual result of computation)?
Hmmm... The cases have to be compile-time constants, so that means strings will be in the constant pool, so I guess the compiler will build the lookups based on something that won't change for a given compiled .class file, regardless of which JVM loads it.

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Hello all,
The following code snippet gives error, please give me guidance.
========
static Object tokenize(StreamTokenizer st)
throws NumberFormatException, IOException {
Object token = null;
try {
if (st.nextToken() == st.TT_EOF) {
throw new EOFException();
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=================
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I can see that working, but
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                } else if(user entered 'S') {
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The errors i get:
16 ')' expected
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                                ^
21: illegal start of expression
                ^
2 errors
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Edited by: Neha Shukla on Dec 3, 2008 1:02 AM
Edited by: Neha Shukla on Dec 3, 2008 1:02 AM
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HOW CAN I PERFORM THE SWITCH STATEMENT INSIDE THIS CODE TO LET IT FULLY FUNCTIONAL..?
I MUST PERFORM THE SWITCH STATEMENT LIKE IN THE QUESTION..
PLEASE HELP ME..REALLY APPRECIATED...TQ

hi
A switch works with the byte, short, char, and int primitive data types. So you can simply give the
switch (month) {
            case 1:
                        System.out.println("January");
                        break;
            case 2: {
                        System.out.println("February");
                         break;
            case 3: {
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moreover u can go to http://www.java-samples.com/java/free_calculator_application_in_java.htm
for reference, just replace the if statement with switch with correct syntax

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import java.awt.*;
import java.awt.event.*;
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Or you can create an int variable say option. Then use an if statement to determine the value of option. Then you can use option in switch statement.
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Multiple rawValues and switch statements - can you do this?

Hi, a simple question (i hope)
first i have to use javascript for his one....
Im just starting a form and it will have about a dozen dropdown lists (over about 15 pages), each with quite a few variables (i feel a headache coming on already...)
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Hey Legallogic!
I'm not 100% certain I understand what you are struggling with but I'd be happy to help. If you could provide an alternate explanation of your issue I'll take a look and help you solve it. What I *think* you're asking about is in reference to the test case of a switch statement. Typically a switch would be used to test the value of one particular variable, so:
switch (varTest)
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Josh Boyle
Cardinal Solutions Group
[email protected]

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Hi all,
Actually i need some more clarification. How to use the same select statement, if i've to use the tabname in the where clause too?
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Thanks & Regards,
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How to use * / - + in a switch statement?

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