title: IE complaining JS syntax error but works on other browsers
body: <p>Javascript function below works fine using Chrome or Firefox. However seem to get a syntax error in Internet Explorer. Its complaining at ` (syntax error) can someone help me as to why? How can I fix this to work on all browsers. </p>
  
  <pre><code>    // Grab the binary mapping of the letter and
  // return some HTML
  function binaryise(letter) {
      var arr = mapping[letter].split('');
      return arr.map(char =&gt; `&lt;div class="${char === '0' ? 'zero' : 'one'}"&gt;${char}&lt;/div&gt;`).join('');
  }
  
  // For each letter in the word create a 
  // binary version and return it in a list-item container
  function processWord(arr) {
      var items = arr.map((letter, i) =&gt; {
          var binaryised = binaryise(letter);
          return `
        &lt;li class="binaryli" data-id=${i}&gt;
          &lt;div class="containerbinary"&gt;${binaryised}&lt;/div&gt;
        &lt;/li&gt;
      `;
      }).join('');
      return `&lt;ul class="binaryul"&gt;${items}&lt;/ul&gt;`;
  }
  </code></pre>