title: Is it safe to modify a Map concurrently?
body: <p>I have a Map that keeps a status of a bunch of checks. Each check will only modify one key using <code>.set</code> will there be any issues if two concurrent checks try to modify the map at the same time?</p>
  
  <p>I have setInterval doing some check in the background and setting the status of the check in a map. In other languages I would have a problem if two things tried to edit the map at the same time. Not actual code but I'm wondering if the following would be safe to do.</p>
  
  <pre><code>var myMap = new Map();
  
  var a = setInterval(someCheckA, 1000);
  var b = setInterval(someCheckB, 1000);
  
  
  function someCheckA() {
      myMap.set('A', 'status is good');
  }
  
  function someCheckB() {
      myMap.set('B', 'status is good');
  }
  
  // do stuff with myMap
  </code></pre>