Mark Hla's answer to Q5

by tonytlwu

HTML

<div id="debug"></div>

JavaScript

function arraySum (i) {
    return sum_parts(i);
}

function sum_parts(val) {
    var sum = 0;
    
    if (val instanceof Array) {
        for (var i = 0; i < val.length; i++) {
            if (val[i] instanceof Array) {
                sum += sum_parts(val[i]);
            } else if (typeof val[i] === "number") {
                sum += val[i];
            }
        }
    }
    
    return sum;
}

var arr = [1,2,3,4,5];
document.getElementById("debug").innerHTML = arraySum(arr);