Why can I create multiple instances with the same name in a loop?

Question

I don't understand why this works and I hope somebody can explain it to me. Here is an example:

TestObject array[] = new TestObject[10];
for(int i= 0; i <= 10; i++){
    TestObject object = new TestObject();

     object.setValue(i);
     array[i] = object;
    System.out.println(array[i].getObject());
}

Why can I create multiple instances of "TestObject" with the same name in the loop? Usually you can't create instances with the same name:

TestObject o = new TestObject(1);
TestObject o = new TestObject(2);

Well, this will obviously throws an error...

possible duplicate of Declaring variables inside or outside of a loop — Whymarrh
– Whymarrh, Commented Nov 1, 2014 at 20:21

Khalid · Accepted Answer · 2014-11-01 20:20:00Z

3

The scope for a for loop is limited to the iteration. So TestObject object is created and destroyed in each iteration.

answered Nov 1, 2014 at 20:20

Khalid

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2 Comments

Manan Shy Over a year ago

Thanks for answering! But I save every instance of TestObject in a global Array. Do they still have the same name in the array?

Khalid Over a year ago

You're not actually storing the objects' names. You're storing the objects' references. If you look inside the array, you'll see an array of unique objects with unique references.

Tabaqui · Accepted Answer · 2014-11-01 20:20:48Z

3

Every iteration of a loop is a block and, as a block, has its own scope. You can achieve the same result by doing this:

{
    int i = 0;
}
{
    int i = 1;
}
// etc

answered Nov 1, 2014 at 20:20

Tabaqui

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Comments

Uhla · Accepted Answer · 2014-11-01 20:20:01Z

0

This is because 'object' is in visibility scope of current loop iteration, so for next iteration, there can be initialized a new one with the same name (other scope).

answered Nov 1, 2014 at 20:20

Uhla

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Comments

Abbas Elmas · Accepted Answer · 2014-11-01 20:23:22Z

0

it's the scope of object problem. every iteration has its scope let's say they are not the same object at all

answered Nov 1, 2014 at 20:23

Abbas Elmas

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