Java variable initialization different ways of handling?

yash Choksi :

I just found that Java handles variable initialization in different ways.

Case-1:

class A {
    boolean x;
    public static void main(String[] args) { 
        A a = new A();
        System.out.println(a.x);
    } 
}

When I ran above program it shows like "false" as output. But now I am posting other piece of code:

Case-2:

class A {
    public static void main(String[] args) {
         boolean x;
         System.out.println(x);
    }
 }

Now, above piece of code shows that

java.lang.Error: Unresolved compilation problem:
    The local variable x may not have been initialized

Why the same thing is handled in very different ways? Thanks in advance!

Michael Krause :

From the Oracle documentation on Java Primitive Data Types:

Local variables are slightly different; the compiler never assigns a default value to an uninitialized local variable. If you cannot initialize your local variable where it is declared, make sure to assign it a value before you attempt to use it. Accessing an uninitialized local variable will result in a compile-time error.

So this is an interesting nuance. If a primitive type variable is locally declared, you must specify a value for it.

Java variable initialization different ways of handling?

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