jQuery中selector,context几种调用方式代码实例详解

<p id="parent" class="parent">
	 <p class="child">
	  child1
	</p>
	<p class="child">
	child2
	</p>
</p>
<p id="parent1" class="parent">
	 <p class="child">
	  child1
	</p>
	<p class="child">
	child2
	</p>
</p>

var doms=$(".child",$("#parent")[0]);
console.log(doms);

var doms=$(".child",$($("#parent")[0]));
console.log(doms);

var doms=$(".child",[document.getElementById("#parent"),document.getElementById("#parent1")]) 
console.log(doms);

 $(function()
  {
    console.log("dom ready");
  })

else if ( selector.nodeType ) {
		this.context = this[0] = selector;
		this.length = 1;
		return this;
		// HANDLE: $(function)
		// Shortcut for document ready
		}

if ( selector.selector !== undefined ) {
			this.selector = selector.selector;
			this.context = selector.context;
		}

 else if ( jQuery.isFunction( selector ) ) {
			return typeof rootjQuery.ready !== "undefined" ?
			rootjQuery.ready( selector ) :
				// Execute immediately if ready is not present
				selector( jQuery );
		}

return jQuery.makeArray( selector, this );

 var $doms=$([document.getElementById('ql'),document.getElementById('fkl')]);
   //把上面的DOM数组封装到新创建的jQuery对象上
   console.log($doms);

              else if ( !context || context.jquery ) {
				return ( context || rootjQuery ).find( selector );
			// HANDLE: $(expr, context)
			// (which is just equivalent to: $(context).find(expr)
			} else {
				return this.constructor( context ).find( selector );
			}

 var doms=$(".child",$(".parent")) ;
   //这时候我们会选择class为parent元素下的所有的class为child的元素集合
   //作为jQuery对象返回
   console.log(doms);