利用不到200行代码写一款属于你自己的js类库

Xuery('#demo').on('click', function(e){
 alert('hello world!')
})

// 访问css
Xuery('#demo').css('width')
// 设置css
Xuery('#demo').css('width', '1024px')
// 设置css
Xuery('#demo').css({
 width: '1024px',
 height: '1024px'
})

// 访问attr
Xuery('#demo').attr('title')
// 设置attr
Xuery('#demo').attr('title', '1024px')
// 设置attrs
Xuery('#demo').attr({
 title: '1024px',
 name: '1024px'
})

// 访问
Xuery('#demo').html()
// 设置
Xuery('#demo').html('前端学习原生框架')

/**
 * 链模式实现自己的js类库
 */
(function(win, doc){
 var Xuery = function(selector, context) {
  return new Xuery.fn.init(selector, context)
 };

 Xuery.fn = Xuery.prototype = {
 constructor: Xuery,
 init: function(selector, context) {
  // 设置元素长度
  this.length = 0;
  // 默认获取元素的上下文document
  context = context || document;
  // id选择符，则按位非将-1转化为0
  if(~selector.indexOf('#')) {
  this[0] = document.getElementById(selector.slice(1));
  this.length = 1;
  }else{
  // 在上下文中选择元素
  var doms = context.getElementsByTagName(selector),
  i = 0,
  len = doms.length;
  for(; i<len; i++){
   this[i] = doms[i];
  }
  }
  this.context = context;
  this.selector = selector;
  return this
 },
 // 增强数组
 push: [].push,
 sort: [].sort,
 splice: [].splice
 };

 // 方法扩展
 Xuery.extend = Xuery.fn.extend = function(){
 // 扩展对象从第二个参数算起
 var i = 1,
 len = arguments.length,
 target = arguments[0],
 j;
 if(i === len){
  target = this;
  i--;
 }
 // 将参数对象合并到target
 for(; i<len; i++){
  for(j in arguments[i]){
  target[j] = arguments[i][j];
  }
 }
 return target
 }

 // 扩展事件方法
 Xuery.fn.extend({
 on: (function(){
  if(document.addEventListener){
  return function(type, fn){
   var i = this.length -1;
   for(; i>=0;i--){
   this[i].addEventListener(type, fn, false)
   }
   return this
  }
  // ie浏览器dom2级事件
  }else if(document.attachEvent){
  return function(type, fn){
   var i = this.length -1;
   for(; i>=0;i--){
   this[i].addEvent('on'+type, fn)
   }
   return this
  }
  // 不支持dom2的浏览器
  }else{
  return function(type, fn){
   var i = this.length -1;
   for(; i>=0;i--){
   this[i]['on'+type] = fn;
   }
   return this
  }
  }
 })()
 })

 // 将‘-'分割线转换为驼峰式
 Xuery.extend({
 camelCase: function(str){
  return str.replace(/\-(\w)/g, function(all, letter){
  return letter.toUpperCase();
  })
 }
 })

 // 设置css
 Xuery.extend({
 css: function(){
  var arg = arguments,
  len = arg.length;
  if(this.length < 1){
  return this
  }
  if(len === 1) {
  if(typeof arg[0] === 'string') {
   if(this[0].currentStyle){
   return this[0].currentStyle[arg[0]];
   }else{
   return getComputedStyle(this[0], false)[arg[0]]
   }
  }else if(typeof arg[0] === 'object'){
   for(var i in arg[0]){
   for(var j=this.length -1; j>=0; j--){
    this[j].style[Xuery.camelCase(i)] = arg[0][i];
   }
   }
  }
  }else if(len === 2){
  for(var j=this.length -1; j>=0; j--){
   this[j].style[Xuery.camelCase(arg[0])] = arg[1];
  }
  }
  return this
 }
 })

 // 设置属性
 Xuery.extend({
 attr: function(){
  var arg = arguments,
  len = arg.length;
  if(len <1){
  return this
  }
  if(len === 1){
  if(typeof arg[0] === 'string'){
   return this[0].getAttribute(arg[0])
  }else if(typeof arg[0] === 'object'){
   for(var i in arg[0]){
   for(var j=this.length -1; j>= 0; j--){
    this[j].setAttribute(i, arg[0][i])
   }
   }
  }
  }
  else if(len === 2){
  for(var j=this.length -1; j>=0; j--){
   this[j].setAttribute(arg[0], arg[1]);
  }
  }
  return this
 }
 })

 // 获取或者设置元素内容
 Xuery.fn.extend({
 html: function(){
  var arg = arguments,
  len = arg.length;
  if(len === 0){
  return this[0] && this[0].innerHTML
  }else{
  for(var i=this.length -1; i>=0; i--){
   this[i].innerHTML = arg[0];
  }
  }
  return this
 }
 })

 Xuery.fn.init.prototype = Xuery.fn;
 window.Xuery = Xuery;
})(window, document);