Deep Copy(Clone) arrays, objects, null, strings, numbers, (no Date)

deep-copy.js

// var testObj = {a: "hello", c: "test", po: 33, arr: [1, 2, 3, 4], anotherObj: {a: 33, str: "whazzup"}};

function deepCopy(o) {
    // if not array or object or is null return self
    if (typeof o !== 'object'||o === null) return o;
    let newO, i;
    // handle case: array
    if (o instanceof Array) {
        let l;
        newO = [];
        for (i = 0, l = o.length; i < l; i++) newO[i] = deepCopy(o[i]);
        return newO;
    }
    // handle case: object
    newO = {};
    for (i in o) if (o[i] !== undefined) newO[i] = deepCopy(o[i]);
    return newO;
}

// var obj2 = deepCopy(testObj);