how to make a request in javascript code example

Example 1: GET req with js

function httpGet(theUrl) {
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.open( "GET", theUrl, false ); // false for synchronous request
    xmlHttp.send( null );
    return xmlHttp.responseText;
}

Example 2: http request javascript

function httpGetAsync(url, callback) {
  var xmlHttp = new XMLHttpRequest();
  xmlHttp.onreadystatechange = function() { 
    if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
      callback(xmlHttp.responseText);
  }
  xmlHttp.open("GET", url, true); // true for asynchronous 
  xmlHttp.send(null);
}