Java - value of primitive type prior to assignment

Question

What is the value of a primitive type prior to an assignment?

What I'd like to do is have a variable that, if set, returns whatever its set to and if not returns null. I recognise that the below is a stupid way of doing it, and I've already solved the problem. However, in thinking about it I realised that I didn't know how primitive types acted prior to assignment and a quick Google didn't show anything. So this is more about answering that question than about finding a better way of solving the problem.

for example:

public class Something{
  int value;
  public Something(){
    //irrelevant stuff
  }

  public int getValue(){
    return value;
  }
}

public class SomeOtherClass{
  public SomeOtherClass(){
    Something s = new Something();
    System.out.println(s.getValue);
  }
}

What would be shown?

score 4 · Accepted Answer · answered May 25 '13 at 10:25

4

An integer class member is initialized by default to 0, if you don't explicitly initialize it yourself.

See http://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.12.5 from the language specification.

answered May 25 '13 at 10:25

Oliver Charlesworth

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Integer class is initialiazed to default null – Alpesh Gediya May 25 '13 at 10:30
Ah, nice find. Wasn't aware of that document. Thank you. – MrB May 25 '13 at 10:30
@AlpeshGediya The subject of the sentence is a class member of type `int`, not a member that is of the `Integer` class. Blame English for having ambiguous syntax. – bcrist Feb 04 '14 at 00:06

score 0 · Answer 2 · edited May 25 '13 at 11:08

0

and in code it is s.getValue() its a method.

edited May 25 '13 at 11:08

Roman C

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answered May 25 '13 at 10:48

R_C

1

Java - value of primitive type prior to assignment

2 Answers2