<pre class="shiki github-dark shaku"><code>Array.prototype.myReduce = function () { // your code here let hasInit = arguments.length &gt; 1 ? true : false if (this.length === 0 &amp;&amp; !hasInit) { throw new Error('TypeError: Reduce of empty array with no initial value') } let accu = hasInit ? arguments[1] : this[0] let i = hasInit ? 0 : 1 for (i; i &lt; this.length; i++) { accu = arguments[0].call(undefined, accu, this[i], i, this,) } return accu}</code></pre>

This is my accepted solution

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Array.prototype.reduce() is a handy method to process arrays. Here is a simple task - Could you implement it by yourself? [1,2,3].myReduce((sum, item)…