编写一个JS组建

dome

window.dome = (function() {
	function Dome(els) {
		for(var i = 0; i < els.length; i++) {
			this[i] = els[i];
		}

		this.length = els.length;
	}

	var dome = {
		get: function(selector) {
			var els;
			if(typeof selector === 'string') {
				els = document.querySelectorAll(selector);
			} else if(selector.length) {
				els = selector;
			} else {
				els = [selector];
			}

			return new Dome(els);
		}
	};

	Dome.prototype.map = function(callback) {
		var results = [], i = 0;
		for(; i< this.length; i++) {
			results.push(callback.call(this, this[i], i));
		}

		return results;
	}

	Dome.prototype.forEach(callback) {
		this.map(callback);
		return this;
	}

	Dome.prototype.someMethod1 = function(callback) {
		this.forEach(callback);
		return this;
	}

	Dome.prototype.someMethod2 = function(callback) {
		return this.forEach(callback);
	}

	return dome;
}());