Enhanced for Loop Vs for Loop

[Gowher Naik]

class Test
{
public static void main( String args[] )
{        
        int []forArr = {1,2,3,4};
        for(int i=0;i<forArr.length;i++){
            forArr[i] = 0;
        }
        for(int i=0;i<forArr.length;i++){
System.out.print(forArr[i]+" ");
}
System.out.println("\n--------------");
int []enhancedForArr = {1,2,3,4};
for ( int i : enhancedForArr ){
enhancedForArr[i] = 0;
}
for ( int i : enhancedForArr ){
System.out.print(i+" ");
}
}
}
 

in above code i am trying to overwrite each element of array by 0
First i overwrite each element of forArr[] array by 0 using for loop
it gives out 0 0 0 0 so it is ok.
But when i try to overwrite each element of enhancedForArr[] by 0
using enhanced for loop it gives output 0 0 3 0

i am not able to understand why.

Thanks

[wise owen]

int [] enhancedForArr = {1,2,3,4};
for ( int i : enhancedForArr ){
enhancedForArr[i] = 0;
}

i = 1 (because enhancedForArr[0]=1) then setting enhancedForArr[1]=0.

i = 0 (because enhancedForArr[1]=0) then setting enhancedForArr[0]=0.

i = 3 (because enhancedForArr[2]=3) then setting enhancedForArr[3]=0.

i = 0 (because enhancedForArr[3]=0) then setting enhancedForArr[0]=0.

then you have 0,0,3,0

[xu yin]

The explanation by wise owen is clear.
Because you overwrite the data "2" before you get it.
If you use "int []enhancedForArr = {0,1,2,3};",
you will get what you want.

Hope I help you partly.

[vidya sagar]

Really Interesting

[Ty Oftrans]

This really is interesting! I am just now trying to understand this very issue (the 'deep' differences between for and enhanced for - if there are any) and this exercise brought out something interesting that would have escaped my attention and understanding.
Thanks for the exercise and for Wise's explanation!

Ty