var obj = {length:0,splice:function(){}} console.log(obj)

var push = Array.prototype.push; var splice = Array.prototype.splice; var a = function() { var a = function(name) { return new a.fn.init(name) } a.fn = a.prototype; a.fn.init = function(name) { 　　　　var arr = document.getElementsByTagName(name); 　　　　merge(this,arr); 　　} a.fn.splice = splice; a.fn.init.prototype = a.fn; return a; }() function merge(first, second) {//完全抄袭jquery中的merge方法- - var i = first.length || 0, j = 0; if( typeof second.length === "number") { for(var l = second.length; j < l; j++) { first[i++] = second[j]; } } else { while(second[j] !== undefined) { first[i++] = second[j++]; } } first.length = i; return first; } a.fn.css = function(pop, val) { for(var i = 0; i < this.length; i++) { if(this[i].nodeType===1){ this[i].style[pop] = val; } } return this; } var ab = a('div'); ab.css('backgroundColor', '#444444').css('borderWidth', '2px').css('borderStyle', 'solid')