javascript

jsonp牵扯到同源策略、跨域等问题，这里不细说了.

实现就是创建动态的script标签来请求后台地址：

示例：

 jsonp('xxx.php', { uid: 1 }, function (res) {
      console.log(res)
    })

实例:

 jsonp('http://localhost/server.php', { uid: 1 }, function (res) {
      console.log(res)
    })

    function jsonp (url, params, callback) {
      var funcName = 'jsonp' + Date.now() + Math.random().toString().substr(2, 5)

      if (typeof params === 'object') {
        var tempArr = []
        for (var key in params) {
          var value = params[key]
          tempArr.push(key + '=' + value)
        }
        params = tempArr.join('&')
      }

      var script = document.createElement('script')
      script.src = url + '?' + params + '&callback=' + funcName
      document.body.appendChild(script)

      window[funcName] = function (data) {
        callback(data)
        delete window[funcName]
        document.body.removeChild(script)
      }
    }