Hide Local Variables

[Ramneek Handa]

Hi there,
Have you heard about the "Hide Local Variables" in java.
This is somebody asked my in an interview.
Can you tell my anything about this.
Thanks for any help

[Sean MacLean]

Well, if you declare them inside of a method then you've basically 'hidden' them from class scope. You can also do the following

public class Test {
  public static void main( String[] args ) {
    int i = 1;
    System.out.println( "outside: " + i );
    // Hide the variable 'j'. 
    {
      int j = 2;
      System.out.println( "inside: " + j );
    }
    // If you uncomment this it won't compile
    // because 'j' is 'hidden' - out of scope.
    //System.out.println( "J outside: " + j );
  }
}

Hope this helps.
Sean

[Ramneek Handa]

Thanks Sean!
Is this the concept called Hiding local variables.

[Ilja Preuss]

No, it isn't.
Hiding local variables is not allowed in java. If it would, you could write something like:

int i = 1;
{
  int i = 2;
  System.out.println(i); // prints "2"
}
System.out.println(i); // prints "1"

That is, the inner variable i "hides" the outer variable of the same name.
In Java, the above code gives a compile time error. On the other hand, local variable *can* hide member variables, as you probably know.