ajax - JavaScript XMLHttpRequest using JsonP - Stack Overflow

JSONP does not use XMLHttpRequests.

The reason JSONP is used is to overcome cross-origin restrictions of XHRs.

Instead, the data is retrieved via a script.

function jsonp(url, callback) {      var callbackName = 'jsonp_callback_' + Math.round(100000 * Math.random());      window[callbackName] = function(data) {          delete window[callbackName];          document.removeChild(script);          callback(data);      };        var script = document.createElement('script');      script.src = (url.indexOf('?') >= 0 ? '&' : '?') + 'callback=' + callbackName;      document.appendChild(script);  }    jsonp('http://www.helloword.com', function(data) {     alert(data);  });

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