<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<script>
$(function(){
 $("#clickBtn").on("click",function(){
  getData(0,10);//输出0-9
 })
})

function getData(i,length){
 $.ajax({
  type:"post",
  url:"setDeffer.php",
  data:{
   data:i
  },
  async:true,//异步
  success:function(data){
   $("#showArea").text($("#showArea").text()+data+"\n");
   if(i<length-1){
    getData(i+1,length);
   }
  }
 });
}
</script>

<?php
$str = $_POST["data"];
sleep(1);//延迟1秒
echo "输出".$str;
?>

<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<script>
$(function(){
 $("#clickBtn").on("click",function(){
  recycleData(0,10);//输出0-9
 })
})

function getData(i){
 var defer = $.Deferred();
 $.ajax({
  type:"post",
  url:"setDeffer.php",
  data:{
   data:i
  },
  async:true,//异步
  success:function(data){
   $("#showArea").text($("#showArea").text()+data+"\n");
   defer.resolve(data);
  }
 });
 return defer.promise();
}
function recycleData(i,length){
 $.when(getData(i)).done(function(data){//这里的data为defer在ajax保存下来的数据
  if(i<length-1){
   recycleData(i+1,length);//递归
  }
 })
}
</script>

function successFunc(){ console.log( “success!” ); } 
function failureFunc(){ console.log( “failure!” ); } 

$.when( 
$.ajax( "/main.php" ), 
$.ajax( "/modules.php" ), 
$.ajax( “/lists.php” ) 
).then( successFunc, failureFunc ); 

$.when($.ajax("test1.html"), $.ajax("test2.html"))
.done(function(){ alert("哈哈，成功了！"); })
.fail(function(){ alert("出错啦！"); });

var defereds = []; //定义一个数组存放Deferred对象

$imgs.each(function() { //imgs循环所有图片
  var dfd = $.Deferred();// 新建一个deferred对象

  $(this).load(dfd.resolve());// 图片加载完成之后，改变deferred对象的执行状态
  defereds.push(dfd);//push到数组中
});
$.when.apply(null, defereds).done(function() {
  console.log('load compeleted');
});

function prints(a,b,c,d){
    console.log(a+b+c+d);
  }
  function example(a,b,c,d){
    prints.apply(this,[a,b,c,d]);
  }
  example("1","sd","wq","wqe") //输出：1sdwqwqe

prints.apply(null,["脚","本","之","家"]);//输出：编程素材网