Insert content, specified by the parameter, before each element in the set of matched elements.
$( “.inner” ).before( “<p>Test</p>” );
$( “.container” ).before( $( “h2” ) );
$( “p” ).first().before( newdiv1, [ newdiv2, existingdiv1 ] );
$( “p” ).before( “<b>Hello</b>” );
$( “p” ).before( document.createTextNode( “Hello” ) );
.insertBefore(target) 把对象插入到target之前（同样不是头部，是同级）
Insert every element in the set of matched elements before the target.
$( “h2” ).insertBefore( $( “.container” ) );
.after([content][,content]) / .after(function（index）) 和before相反，在对象后面(不是尾部，而是外面，和对象并列同级)插入内容，参数和append类似
Insert content, specified by the parameter, after each element in the set of matched elements.
$( “.inner” ).after( “<p>Test</p>” );
$( “p” ).after( document.createTextNode( “Hello” ) );
.insertAfter(target) 和insertBefore相反，把对象插入到target之后（同样不是尾部，是同级）
Insert every element in the set of matched elements after the target.
$( “<p>Test</p>” ).insertAfter( “.inner” );
$( “p” ).insertAfter( “#foo” );
包裹元素
.wrap(wrappingElement) / .wrap(function(index)) 为每个对象包裹一层HTML结构，可以是selector, element, HTML string, jQuery object
Wrap an HTML structure around each element in the set of matched elements.
<div class=”container”>
<div class=”inner”>Hello</div>
<div class=”inner”>Goodbye</div>
</div>$( “.inner” ).wrap( “<div class=’new’></div>” );
<div class=”container”>
<div class=”new”>
<div class=”inner”>Hello</div>
</div>
<div class=”new”>
<div class=”inner”>Goodbye</div>
</div>
</div>
.wrapAll(wrappingElement) 把所有匹配对象包裹在同一个HTML结构中
Wrap an HTML structure around all elements in the set of matched elements.
<div class=”container”>
<div class=”inner”>Hello</div>
<div class=”inner”>Goodbye</div>
</div>$( “.inner” ).wrapAll( “<div class=’new’ />”);<div class=”container”>
