title: Why can I not push a number into my array of strings even though I have converted the number back to a string?
body: <p>Hello there I am trying to do a code wars kata: <a href="https://www.codewars.com/kata/54a91a4883a7de5d7800009c/train/javascript" rel="nofollow noreferrer">https://www.codewars.com/kata/54a91a4883a7de5d7800009c/train/javascript</a></p>
  <p>I know what I have done is very long-winded but I wanted to do it step by step before I refactored it.</p>
  <ol>
  <li>I have split the string input from the user</li>
  <li>Filtered through the array just to get the number and converted it to a NUMBER</li>
  <li>Incremented that number by 1</li>
  <li>Changed number back to string</li>
  <li>Now I want to add my string number to the original array but it doesn't work and I don't understand  why :S</li>
  </ol>
  <p>I know this is not the final answer to the kata but I am just trying things and wondered why this did not work...</p>
  <pre><code>function isNumeric(num){
   return !isNaN(num)
  }
  
  function incrementString (string) {
    const splitString = string.split(&quot;&quot;);
  
    let numbers = Number(splitString.filter(el =&gt; isNumeric(el)).join(&quot;&quot;)); //[
    'f', 'o', 'o', 'b',
    'a', 'r', '0', '0',
    '4', '2'
  ]
  
    let incrementNumber = numbers +=1; // 43
  
    let revertNumberToString = incrementNumber.toString(); // &quot;43&quot;
  
    let test = splitString.push(revertNumberToString); // why can I not push the number 43 onto my original array?
  
    console.log(test); // 11? why?
  
  }
  
  incrementString(&quot;foobar0042&quot;)
  </code></pre>