<pre class="shiki github-dark shaku"><code>function count(str) { let max = 0; const dict = {}; const res = []; str.split('').map(letter =&gt; { dict[letter] === undefined ? dict[letter] = 1 : dict[letter] = dict[letter] + 1; if(dict[letter] &gt; max){ max = dict[letter]; } }); for(let letter in dict){ if (dict[letter] === max) res.push(letter); } return res.length &gt; 1 ? res : res[0];}</code></pre>

my solution

Given a non-empty string, return the most frequently ocurring character. If there are multiple characters with same occurrance, return an array of the…