<div name="students" school="HK"> 
 <input type="boy" name="ZhangSan" value="206"> 
 <input type="girl" name="Lisi" value="108"> 
 </div> 

<script type="text/javascript"> 
 /* find() 查找子元素方法 */ 
 var aaa = $("div[name='students'][school='HK']").find("input[type='boy'][name='ZhangSan']"); 
 console.log(aaa.val()); 
  
 /* $(".child",parent); 方法查找子元素*/ 
 var bbb = $($("input[type='boy'][name='ZhangSan']"),$("div[name='students'][school='HK']")); 
 console.log(aaa.val()); 
 
 /* each()方法遍历数组 */ 
 var arr = [ "one", "two", "three", "four" ]; 
 $.each(arr, function() { 
  console.log(this); 
 }); 
  
 /* each()方法处理json */ 
 var obj = { 
  one : 1, 
  two : 2, 
  three : 3, 
  four : 4 
 }; 
 $.each(obj, function(key, val) { 
  console.log(obj[key]); 
 }); 
  
 /* each()方法处理二维数组 */ 
 var arr1 = [ [ 11, 44, 33 ], [ 4, 6, 6 ], [ 7, 20, 9 ] ] 
 $.each(arr1, function(i, item) { 
  console.log(item[0]); 
 }); 
 
 /* each()方法处理HTML元素 */ 
 $("div[name='students'][school='HK'] > input").each(function() { 
  console.log($(this).val()); 
 }); 
 </script>