前端javascript练习题Ajax封装

前端javascript练习题Ajax封装
ajax的基本封装 ----必须掌握
function ajax(url,fn){

if(window.XMLHttpRequest){ var xhr = new XMLHttpRequest(); }else{ var xhr = new ActiveXObject("Microsoft.XMLHTTP"); } xhr.open("get",url,true); xhr.send(); xhr.onreadystatechange = function(){ if(xhr.readyState == 4){ if(xhr.status == 200){ var data = xhr.responseText; fn(data); } } }} 

ajax的完整封装
function ajax(obj){

//obj -> type url data success var str = ""; for(var key in obj.data){ str += key+"="+obj.data[key]+"&"; } //str = str.substring(0,str.length-1); str = str.replace(/&$/,""); if(window.XMLHttpRequest){ var xhr = new XMLHttpRequest(); }else{ var xhr = new ActiveXObject("Microsoft.XMLHTTP"); } if(obj.type.toUpperCase()=="GET"){ if(obj.data){ var url = obj.url + "?" + str; }else{ var url = obj.url; } xhr.open("get",url,true); xhr.send(); } if(obj.type.toUpperCase()=="POST"){ xhr.open("post",obj.url,true); xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); xhr.send(str); } xhr.onreadystatechange = function(){ if(xhr.readyState == 4){ if(xhr.status == 200){ var data = xhr.responseText; obj.success(data); } } }