简短的加载JS方法

LoadScript.js

/**
 * 加载JS
 */
function LoadScript(url, callback){
  var urls = typeof url === 'string' ? [url] : url;

  if (!Array.isArray(urls)){
    throw 'argument type error';
    return;
  }
  if (urls.length <= 0){
    callback();
    return;
  }

  var head = document.head;
  var script = document.createElement('script');

  script.src = urls[0];
  script.async = false;
  script.type = 'text/javascript'
  script.charset = 'utf-8'

  head.appendChild(script);

  script.onload = script.onerror = function(){
    script.onload = script.onerror = null;
    LoadScript(urls.slice(1), callback);
  };
}