看了你不少文章，路过写写

[noneven]

var jsonP = (function(){

    var root = this;

    var param2query = function(data){
        var query = "?";
        for(var k in data){
            if(!data.hasOwnProperty(k)) break;
            query+= (k)+"="+(data[k])+"&";
        }
        return query;
    };

    return function(url, option){

        var data, callback;

        if ("[object Object]" == Object.prototype.toString.call(url)) {
            url = url.url;
            data = url.data;
            callback = url.callback;
        }else{
            data = option.data;
            callback = option.callback;
        }

        var jsonPCallbackName = "jsonP" + new Date().getTime();

        url = url.replace(/\?$/,"") + param2query(data);

        url += "callback=" + jsonPCallbackName;

        var script = document.createElement("script");
        script.src = url;

        root[jsonPCallbackName] = function(data){
            callback.call(jsonP, data)
            delete root[jsonPCallbackName];
            document.body.removeChild(script)
        }

        document.body.appendChild(script);
    }
}).call(this);

jsonP("https://passport.58.com/wukong/userstate", {
    data: {
        user: "cat",
        pword: "any"
    },
    callback: function(data) {
        console.log(data)
    }
})

少个umd封装

[island205]

if(!data.hasOwnProperty(k)) break; 为什么要 break ？

[noneven]

我不太喜欢

if(true){
    //todo
    if(true){
        //todo
    }
}
//习惯这样
if (!false) return 
if (!false) break
if (!false) continue