ajax实现数据提取

function ajax(options){
    return new Promise(function(resolve,reject){
        var xhr = new XMLHttpRequest() || ActiveXObject("Microsoft,XMLHTTP");
        //拼接参数
        var str = "";
        if(options.data){
             for(key in options.data){
                str += '&' + key + "=" + options.data[key];
            }
        };
        //判断提交方式
        if(options.method == 'get'){
            xhr.open("get",options.url + "?" + str.slice(1));
            xhr.send();
        }else{
            xhr.open("post",options.url);
            xhr.setRequestHeader("content-type","application/x-www-form-urlencoded");
            xhr.send(str.slice(1));
        };
        xhr.onreadystatechange = function(){
            //如果请求成功的情况下 数据直接交给 resolve(data);
            if(xhr.readyState == 4 && xhr.status == 200){
                resolve(JSON.parse(xhr.responseText));
            }

            //如果数据请求失败  
            setTimeout(function(){
                if(xhr.readyState != 4 || xhr.status != 200){
                    var objState = {
                        state : xhr.readyState,
                        status :  xhr.status
                    };
                    reject(objState)  //reject只能返回一个结果
                }
            },3000)    //异步指向需要等待
        } 
    })
}
//调用该方法示例
/*
    document.onclick = function(){
        ajax({
        'method' : 'get',
        'url' : 'http://localhost/data.php',
        'data': {
            'id' : 'VIP'
        }
    }).then(function(data){
        console.log(data);
    }).catch(function(data){
        console.log(data)
    })
    }
*/

下面是被提取的一个php文件示例

<?php
    header("content-type:text/html;charset:utf8");
    $vip = $_REQUEST["id"];
    $arr = Array(
        Array(
            "id" => "1",
            "name" => "小红"
        ),
        Array(
            "id" => "2",
            "name" => "小亮"
        ),
        Array(
            "id" => "3",
            "name" => "小明"
        ),
        Array(
            "id" => $vip,
            "name" => "小瑶"
        ),
        Array(
            "id" => "5",
            "name" => "小飞"
        )
    );
    echo json_encode($arr);
?>