How to return multiple values from one method??

[Bartec]

Hi!

I'm quite new in Java, so please tell me how I can return multiple values from one method? In C++ I uses pointers but what about java?? Thanks for any advise and help.

Best regards

Bartec

 

[sedj]

In short, you cannot.

If you really need to "return" more than one value, you need to set up a data holder, eg :

class DataHolder {
  public int anInt = -1;
  public String aString = null;
}

And then in your method :

public DataHolder myMethod() {
  DataHolder dh = new DataHolder();
  dh.anInt = 9;
  dh.aString = "Hello";

  return dh;
}

Then your calling method unpacks the DataHolder class :

DataHolder dataHolder = myMethod();
int i = dataHolder.anInt;
String s = dataHolder.aString;

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[timw]

You can obviously only return one thing from a method. If you want to return several values, then you could define a class to hold these values and return an instance of it from the method.

public class MyReturnValue {
  private int value1;
  private int value2;

  public MyReturnValue(int val1, int val2){
    this.value1 = val1;
    this.value2 = val2;
  }

  public int getValue1(){
    return value1;
  }

  public int getValue2(){
    return value2;
  }
}

Then this would be used :-

public class SomeClass {

  public MyReturnValue doSomething(){
    //... do some stuff
    return new MyReturnValue(1,2);
  }
}

This would return values 1 and 2, held in the instance of MyReturnValue. You can obviously substitute the 1 and 2 for other values, perhaps from variables. Change the MyResultValue class to hold values of the types you want.

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[timw]

sedj, we're doing that 'simultaneous reply' thing again !

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[sedj]

Lol, beat you



--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[timw]

I'm gonna have to register a new username that starts with a letter before S in the alphabet. Then this forum might put me first, eh?

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[chrissie1]

I think it's by age.

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[timw]

Oh dear, I'm scuppered then!

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy