title: How does `Array.from({length: 5}, (v, i) => i)` work?
body: <p>I may be missing something obvious here but could someone breakdown step by step why <code>Array.from({length: 5}, (v, i) =&gt; i)</code> returns <code>[0, 1, 2, 3, 4]</code>?</p>
  
  <p><a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/from" rel="noreferrer">https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/from</a></p>
  
  <p>I didn't understand in detail why this works</p>