js 重写集合remove方法

Array.prototype.remove = function (dx) {
if (isNaN(dx) || dx > this.length) { return false; }
for (var i = 0, n = 0; i < this.length; i++) {
if (this[i] != this[dx]) {
this[n++] = this[i]
}
}
this.length -= 1
}