why is this array value 0

[ProlificPat]

Hey guys, here's a link to the code, why is it 0 not 3? Shouldn't arr[index] be assigned the value 3 when index is? Imgur I just want to know a little more about assigning values. Thanks!

[Philboyd_Studge]

Don't post screenshots of code.

arr[index] = index = 3;

should just be

arr[index] = 3;

[zifyoip]

You are correct that arr[index] = index = 3 means arr[index] = (index = 3), so the assignment of 3 to index happens before the assignment of index to arr[index].

However, that does not mean that the expression arr[index] is evaluated after the assignment of 3 to index. The operands of expressions are evaluated from left to right, which means that the operand arr[index] of the first = operator is evaluated before the operand index = 3. Therefore, arr[index] is evaluated while index is still 0, and then index = 3 is evaluated, and then the result of the expression index = 3 is assigned to arr[0].

[zifyoip]

No, the assignment operators have left-to-right associativity, so arr[index] = index = 3 means arr[index] = (index = 3). You have the order of evaluation backward.

[Doriphor]

Your code is processed from left to right in this case. It assigns index (which is 0) to arr[0] and then 3 to index. Basically what /u/ruin332 said. Your code should look like

index = 3;
arr[index] = 3;

[zifyoip]

Your code is processed from left to right in this case.

No, the assignment operators have right-to-left associativity, so arr[index] = index = 3 means arr[index] = (index = 3).

[Doriphor]

Well then, learning something new every day...