JavaScript Array Insert and Bisect

array.insert.js

Array.prototype.bisect = function (val) {
    var idx;
    if (this.length === 0) {
        return 0;
    }
    for (idx=0; idx < this.length; idx++) {
        if (val < this[idx]) {
            return idx;
        }
    }
    return idx;
};

Array.prototype.insert = function (val, inPlace) {
    var idx = this.bisect(val);
    if (inPlace) {
        this.splice(idx, 0, val);
        return this;
    }
    return this.slice(0, idx).concat([val], this.slice(idx));
};