legacy pattern by me for async fetching multiple urls

asyncFetchForEs5

(function() {
  var inputUrls = ['https://same.origin.pages', ...];  //input
  var result = [];  //global var for output

  getTextFromUrls(inputUrls);
  function getTextFromUrls(urlArray) {
    var urls = urlArray.slice();
    asyncFetch(urls.pop());

    function asyncFetch(url) {
      console.log(url);
      var xhr = new XMLHttpRequest();
      xhr.onreadystatechange = function() {
        if(xhr.readyState==4 && xhr.status==200) 
          fetchSuccess(xhr.responseText);  //no error-handling for brevity
      };
      xhr.open('GET', url);
      xhr.send();
    }

    function fetchSuccess(txt) {
      result.push(txt.slice(0, 256));  //processing response
      
      if(urls.length == 0)
        loadEnd();
      else 
        asyncFetch(urls.pop());
    }
  }

  function loadEnd() {
    console.log('done!');
    console.log(result);
    
    //or another entry point
  }
  
})();