title: Return value using arrow syntax
body: <p>So to my understanding which is obviously wrong at this moment in time is that,</p>
  
  <pre><code>return arg =&gt; arg*2
  </code></pre>
  
  <p>is the same as </p>
  
  <pre><code>return (arg)=&gt;{arg*2}
  </code></pre>
  
  <p>I always assumed arrow functions are just syntactically neater.</p>
  
  <p>But doing this with closures like so doesn't work.</p>
  
  <pre><code>function addTwoDigits(firstDigit){
      return (secondDigit)=&gt;{firstDigit + secondDigit}
  }
  let closure = addTwoDigits(5);
  console.log(closure(5)) // Undefined
  </code></pre>
  
  <p>Yet this is fine </p>
  
  <pre><code>function addTwoDigitsV2(firstDigit){
      return secondDigit =&gt; firstDigit + secondDigit
  }
  let closure2 = addTwoDigitsV2(10);
  console.log(closure2(10))// 20
  </code></pre>