如何动态加载来自不同域的javascript文件？

function loadScript(url, callback) {
  var script = document.createElement("script");
  script.type = "text/javascript";
  script.src = url;

  if (script.readyState) {  // for Internet Explorer
    script.onreadystatechange = function() {
      if (script.readyState == "loaded" || script.readyState == "complete") {
        script.onreadystatechange = null;
        callback();
      }
    };
  } else {  // for other browsers
    script.onload = function() {
      callback();
    };
  }

  document.getElementsByTagName("head")[0].appendChild(script);
}

// 使用示例
loadScript("https://example.com/script.js", function() {
  // 在这里执行回调函数
});