<pre class="shiki github-dark shaku"><code>/** * @param {string} str * @return {object | Array | string | number | boolean | null} */function parse(str) { if(str === '') { throw Error(); } if(str[0] === "'") { throw Error(); } if(str === 'null') { return null; } if(str === '{}') { return {}; } if(str === '[]') { return []; } if(str === 'true') { return true; } if(str === 'false') { return false; } if(str[0] === '"') { return str.slice(1, -1); } if(+str === +str) { return Number(str); } if(str[0] === '{') { return str.slice(1, -1).split(',').reduce((acc, item) =&gt; { const index = item.indexOf(':'); const key = item.slice(0, index) const value = item.slice(index + 1); acc[parse(key)] = parse(value); return acc; }, {}); } if(str[0] === '[') { return str.slice(1, -1).split(',').map((value) =&gt; parse(value)); }}</code></pre>

This is my accepted solution

This is a follow-up on 21. implement JSON.stringify(). Believe you are already familiar with JSON.parse(), could you implement your own version? In ca…