这是一个纯注释JavaScript示例。

  <script language="JavaScript" type="text/javascript">
  function iterate_json(){
            // Create our XMLHttpRequest object
            var hr = new XMLHttpRequest();
            // Create some variables we need to send to our PHP file
            hr.open("GET", "json-note.php", true);//this is your php file containing json

            hr.setRequestHeader("Content-type", "application/json", true);
            // Access the onreadystatechange event for the XMLHttpRequest object
            hr.onreadystatechange = function() {
                if(hr.readyState == 4 && hr.status == 200) {
                    var data = JSON.parse(hr.responseText);
                    var results = document.getElementById("myDiv");//myDiv is the div id
                    for (var obj in data){
                    results.innerHTML += data[obj].id+ "is"+data[obj].class + "<br/>";
                    }
                }
            }

            hr.send(null); 
        }
</script>
<script language="JavaScript" type="text/javascript">iterate_json();</script>// call function here

var arr = [{" id ":“10”,“类”:" child-of-9 "}, {" id ":“11”,“类”:“child-of-10”}); For (var I = 0;I < arrr .length;我+ +){ 文档。写("<br><br>数组索引:" + i); Var obj = arr[i]; For (var key in obj){ Var值= obj[key]; 文档。Write ("<br> - " + key + ": " + value "); ｝ ｝

注意:for-in方法对于简单对象很酷。与DOM对象一起使用不是很明智。

从http://www.w3schools.com复制和粘贴，不需要JQuery开销。

var person = {fname:"John", lname:"Doe", age:25};

var text = "";
var x;
for (x in person) {
    text += person[x];
}

结果:无名氏25人

如果这是你的数据数组:

var dataArray = [{"id":28,"class":"Sweden"}, {"id":56,"class":"USA"}, {"id":89,"class":"England"}];

然后:

$(jQuery.parseJSON(JSON.stringify(dataArray))).each(function() {  
         var ID = this.id;
         var CLASS = this.class;
});

对于嵌套对象，可以通过递归函数检索:

function inside(events)
  {
    for (i in events) {
      if (typeof events[i] === 'object')
        inside(events[i]);
      else
      alert(events[i]);
    }
  }
  inside(events);

其中as events是json object。

你可以使用像objx - http://objx.googlecode.com/这样的迷你库

你可以这样写代码:

var data =  [ {"id":"10", "class": "child-of-9"},
              {"id":"11", "class": "child-of-10"}];

// alert all IDs
objx(data).each(function(item) { alert(item.id) });

// get all IDs into a new array
var ids = objx(data).collect("id").obj();

// group by class
var grouped = objx(data).group(function(item){ return item.class; }).obj()

还有更多的“插件”可以让你这样处理数据，请参阅http://code.google.com/p/objx-plugins/wiki/PluginLibrary