$('div').slice(1,3).css('background','red').end().css('color','blue'); 入栈原理图：
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script src="jquery-2.0.3.js"></script>
<script> $(function(){
console.log( $('div'));//json对象Object { 0: <div>, 1: <div>, 2: <div>, 3: <div>, length: 4, prevObject: Object, context: HTMLDocument → new%202.html, selector: "div" } console.log( $('div').toArray() );//Array [ <div>, <div>, <div>, <div> ] $('div') : { 0 : div , 1 : div , 2 : div , length : 3 } $('div').toArray() : [div,div,div] $('div').get(-1).innerHTML = '222222222'; for(var i=0;i<$('div').get().length;i++){
$('div').get(i).innerHTML = '222222';
} /*$('div').pushStack( $('span') )，pushStack()返回span，span的prevObject等于div，css('background','red')只会把span变红，
end: function() {
return this.prevObject || this.constructor(null);
},
调用end方法就是返回prevObject就实现了栈，多次调用end()，最后返回空,就不处理最后的css方法。*/ $('div').pushStack( $('span') ).css('background','red').end().end().end().css('background','yellow');
/*
slice: function() {
return this.pushStack( core_slice.apply( this, arguments ) );
},
core_slice = core_deletedIds.slice, core_deletedIds = [],
$('div').slice(1,3)返回2.3两个div,他的prevObject = $('div')（4个div），css('background','red')就是把2个div变红，end().css('color','blue')把4个div变蓝。*/ $('div').slice(1,3).css('background','red').end().css('color','blue'); /*
eq: function( i ) {
var len = this.length,
j = +i + ( i < 0 ? len : 0 );
return this.pushStack( j >= 0 && j < len ? [ this[j] ] : [] );
},
*/
$('div').eq(0).css('background','red');
var arr = ['a','b','c']
arr = $.map(arr,function(elem,i){
return elem + i;
});
alert( arr );//[a0,b1,c2] }); </script>
</head> <body>
<div>div</div>
<div>div</div>
<div>div</div>
<div>div</div>
<span>span</span>
</body>
</html>