title: array.splice vs setting a value to null
body: <blockquote>
    <p>You should use <code>array.splice(i, 1);</code> instead of <code>array[i] = null</code> This will preserve the keys in the array</p>
  </blockquote>
  
  <p>Source : <a href="https://stackoverflow.com/questions/33388729/should-i-bother-cleaning-array-in-node-js">Should I bother cleaning array in node.js?</a></p>
  
  <p>I don't really understand this sentence. Why <code>array[i] = null</code> will change the keys of the array ? Why <code>array.splice(i, 1);</code> is better ?</p>