Destroy object

[anjanesh]

Hi

How do I reuse the same object-name ?

String s = new String("a-string");
System.out.println(s);
s = null;

Integer s = new Integer(5);
System.out.println(s);

Main.java:19: s is already defined in main(java.lang.String[])
                String s = new String("b-string");

I thought setting it to null would destroy it.

Thanks

[rajiv_bang]

Anjanesh,

The code is trying to reuse the variable 's' and not an object (a reference actually). It is trying to declare a variable 's' again as an Integer when it has already been declared a few lines above as a String reference variable.

Variable names in the same scope should be unique. You cannot have two variables with the same name in the same scope.

However, if you want to use the same reference variable to point to a different object, you can do so.

HTH

	String s = new String("a-string");
	System.out.println(s);
	s = null;

	s = new String("b-string");
	System.out.println(s);

[anjanesh]

Is there any way to destroy a variable so that it can be used to assign it to another type ?

[CaptainMorgan]

Is there any way to destroy a variable so that it can be used to assign it to another type ?

Rajiv will correct me if I'm wrong, but I'm pretty sure he answered this question.

Variable names in the same scope should be unique. You cannot have two variables with the same name in the same scope.

However, if you want to use the same reference variable to point to a different object, you can do so.

[Lil_Aziz1]

I am trying to reuse a variable for the same obj. but i'm getting an error:
Mnemonic a = new Mnemonic(4);
a = null;
Mnemonic a = new Mnemonic(5);

ERROR:
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
Duplicate local variable a

this is in eclipse

[Fubarable]

So then
1) Don't have a second declaration of the variable, just use it.
i.e., not

Mnemonic a = new Mnemonic(4);
a = null;
Mnemonic a = new Mnemonic(5);

but instead

Mnemonic a = new Mnemonic(4);
// a = null; // this isn't necessary
a = new Mnemonic(5);

2) Please don't resurrect long dead threads. If you have a question of your own, create a new thread here in the forum for this question.

[AndreB]

oh, i see its an old problem, but one can avoid it if one set the right parenthesis

{
String s = new String("a-string");
System.out.println(s);
s = null;
}
{
Integer s = new Integer(5);
System.out.println(s); 
}

yay !

[[RaIdEn]]

oh, i see its an old problem, but one can avoid it if one set the right parenthesis

{
String s = new String("a-string");
System.out.println(s);
s = null;
}
{
Integer s = new Integer(5);
System.out.println(s); 
}

yay !

yup you can do that..i think the OP is confused with the concept of garbage collector

Garbage

[Lil_Aziz1]

w8 so if you don't use { and }, you can't reuse a variable name for a different obj? how come?

[AndreB]

"{" and "}" declares a code block like "begin" and "end". after "}" there is no variable "s" and therefore you can declare it again (Scope (programming) - Wikipedia, the free encyclopedia)

[Lil_Aziz1]

ohh alrigh. its like this basically:

public class Test {

public void test1() {
int s = 5;
.....
}
public void test2() {
String s = "hi";
.....
}
}

[AndreB]

no rather

if (true) {
   ...
}