How to change value by reference?

[chris83190@hotmail.com]

Here is an example code:

package test;

public class Test {

    static boolean test (String someString) {
        boolean anotherBool = true;
        someString = "IWantThisString";
        
        return anotherBool;
    }

    public static void main(String[] args) {
        String someString = "NotThisString";
        boolean someBool = false;
        
        someBool = test(someString);
        System.out.println(someBool + " " + someString);
        
        //It prints the following:
        //true NotThisString
    }
}

how can i get someString to become "IWantThisString" and print that out?
Im trying to get it work for another project
Restrictions are that I use that boolean function.

[sunde887]

I'm not sure what you want is really possible. I could be wrong and I will learn something if I am.

If you have an instance variable you can have the method change the variable.

As far as I know you are passing in a copy to the method and I don't believe you can pass in a reference.

Check this link out http://www.javaworld.com/javaworld/j...0526-pass.html

[Fubarable]

Strings are immutable so what you are trying to do is impossible. It will work if you use a static class variable.

public class Test {
   static String otherString = "Not this String";
   
   static boolean test(String someString) {
      boolean anotherBool = true;
      someString = "IWantThisString";
      
      otherString = "I want this String";

      return anotherBool;
   }

   public static void main(String[] args) {
      String someString = "NotThisString";
      boolean someBool = false;

      someBool = test(someString);
      System.out.println(someBool + " " + someString);
      System.out.println(otherString);

      // It prints the following:
      // true NotThisString
   }
}

[chris83190@hotmail.com]

edit:
ahh you guys edit your posts too fast.

thanks for the linky sunde887

and thanks fubarable, i will look into that.

[pbrockway2]

Restrictions are that I use that boolean function.

??? But you've just seen that that boolean method does not do what you want.

There's yucky: have a static variable or pass an array or an instance of some contrived class.

And there's nice: return the string and assign it to someString.

--------------

If you use a variable as a parameter in some method call then that variable will have the same value after the method has finished. Every variable, every time. That's just how Java works.

If you want to change the value a variable has you assign something to it. (Including, in this case, the thing returned by a method.)

-------------

I'm not sure the immutability of strings has anything to do with this.

[pbrockway2]

Since it's been raised, here's a discussion of passing, and values:

JavaRanch Campfire - Cup Size: a Story About Variables
JavaRanch Campfire - Pass By Value, Please