How arr comes after x :

Answer 1

Please post code.

Answer 2

@r
This is a for each loop. Iterates through the whole array. You need to init the array before looping through it.

Answer 3

int total =0;
for(int x : arr){
total += x;
}

Answer 4

enhanced for loop

Answer 5

total question should be like below:
int[] arr={2,3,5,7};
int total=0;
for (int x: arr) {
total +=x;
}

but they have removed the first line. Hope now you understood this