Why did the global variable array become empty outside the function?

• 0
  There is a small script on node.js that first receives an array of id, then mixes them up, then searches for people's names by id and writes a new array.
  But by declaring the global variable arrName, it is impossible to display this array, or rather it is empty for some reason.
  
  

  function shuffle(array) {
      array.sort(() => Math.random() - 0.5);
  }
  const arrName = [];
  const XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
  const x = new XMLHttpRequest();
  x.open('GET', 'https://slack.com/api/conversations.members?token=xxx&channel=xxx');
  x.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
  x.onload = function() {
      let array_1 = JSON.parse(this.responseText).members;
      shuffle(array_1);
      var array_cleaned = array_1.filter(function(element) {
          return element.length <= 9;
      });
      var array_cleaned2 = array_cleaned.filter(function(element2) {
          const y = new XMLHttpRequest();
          y.open('GET', 'https://slack.com/api/users.profile.get?token=xxx&user=' + element2);
          y.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
          y.onload = function() {
          let array_2 = JSON.parse(this.responseText).profile.display_name;
              console.log('В группе состоит ' + array_2);
          arrName.push(array_2);
          }
          y.send();
      });
      console.log(array_cleaned);
      console.log(arrName);
  }
  x.send();

  
  
  Why console.log (arrName);
  outputs just an empty array?
  Moreover, if I check arrName after the line "arrName.push (array_2);" , then the array is output (which is logical 3 times)

  JavaScript Paige Bullock, Dec 18, 2019

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2 Answers
• 0
  Asynchronous requests.
  
  
  
  console.log (arrName) - displayed before everything in array_cleaned2 is executed

  Anonymous

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• 0
  Because you fill it inside the callback, which at the time of the output console.log (arrName)
  
  has not been called yet.
  
  Put the output after the line
  
  arrName.push (array_2);
  
  
  
  to make sure that an empty array is displayed first, and then it starts filling

  Paige Calderon

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