title: indexOf() with for loop
body: <p>I am trying to check if the first element of the array contains all letters from the second element of the array. But it doesn't work properly on this given properties. I can't find where do I do a mistake?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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  <pre class="snippet-code-js lang-js prettyprint-override"><code>function mutation(arr) {
    var first = arr[0].toLowerCase();
    var second = arr[1].toLowerCase();
    
      for(i = 0; i&lt;second.length; i++){
       return first.indexOf(second[i]) !== -1 ? true : false;
      }
  
  
  }
  
  mutation(["hello", "hey"]);</code></pre>
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  </div>
  </p>