Scope of variable inside for loop

Question

This function returns the total from an array, and it works perfectly. But if i initialize total inside the for loop, it does not return the sum. Can you please tell me why?

function sum(arr) {
    var total=0;

    for (var i=0;i<arr.length;i++){
        total += arr[i];
    }

    return total;
}

When you initialize a variable inside the loop, you are creating a new variable with the assigned value every time. Hence the previous value is lost. — rdp
– rdp, Commented Aug 11, 2014 at 21:41

Pointy · Accepted Answer · 2014-08-11 21:38:21Z

3

If you initialize it inside the loop, then the initialization happens on each iteration. I would use the word "reinitialize" in fact. I mean, it's just basic control flow — you initialize an accumulator variable before the loop begins, and then you modify it on each iteration of the loop.

answered Aug 11, 2014 at 21:38

Pointy

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