Codec ░ Sums and NaNs in Javascript

779Sums and NaNs in Javascript

var array = [132, 32, 14, 525, 52, 12, 52];
var sum;
for (var i=0; i<array.length; i++ ) {
	sum += array[i];
	console.log(sum);
}

I was slightly puzzled, why the above code outputs Nan instead of the consecutive sums of the array.

var array = [132, 32, 14, 525, 52, 12, 52];
var sum = 0; // sum needs to be init...?
for (var i=0; i<array.length; i++ ) {
	sum += array[i];
	console.log(sum);
}

After declaring sum with a number, it works. Still have to find out why.