reduce in js info code example
Example 1: javascript reduce
var array = [36, 25, 6, 15];
array.reduce(function(accumulator, currentValue) {
return accumulator + currentValue;
}, 0); // 36 + 25 + 6 + 15 = 82
Example 2: reduce mdn
array.reduce(callback( accumulator, valueNow[, index[, array]] )[, initialValue]))