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# verry confusing array !!!!

Greenhorn
Posts: 5
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Hi..
Iam very confused with this array.
Plzz tell me ...how to evaluate the expression -
(a [ (a = b) [ 3 ]] )
class testarry
{
public static void main(String[ ] args)
{
int[ ] a = { 1, 2, 3, 4 };
int[ ] b = { 2, 3, 1, 0 };
System.out.println( a [ ( a = b )[3]] );
}
}
The program prints 1. why???
S U N I T.

Ranch Hand
Posts: 75
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Hi Sunitkumar Survase:
(a [ (a = b) [ 3 ]] )
In this experssion you may notice there are 2 arrays(outer a[] array and an inner (a=b)[3]---> b[3] array) both arrays will be get evaluvated to
a[b[3]]
b[3] is 0.
So a[0]. which in turn will give 1
-Siva

Greenhorn
Posts: 29
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Hi Sunit,
It is all about operator precedence.
First a[i] is computed and printed, where 'i' is (a=b)[3].
To evaluate (a=b)[3], first assign array b into a, then take the subscript [3]. So a and b are denoting the same array { 2, 3, 1, 0 }. Thus i is equal to 0 (a[3] / b[3]). But as I mentioned before, a[i] is evaluated first. So a[0] from original array a ({ 1, 2, 3, 4 }) is printed. If you analyze array a after this 'println' statement, you will find that a referencing the array b ({ 2, 3, 1, 0 }).
Bala Arul.

Sunitkumar Survase
Greenhorn
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Thanxx a lot.
I got it.
Cheers,
Sunit

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