Here is a video explaining <a href="https://www.youtube.com/watch?v=wE3PmZyVNsU">https://www.youtube.com/watch?v=wE3PmZyVNsU</a>
<pre class="shiki github-dark shaku"><code>// 1. for loop approachfunction range(from, to) { // return the result array const result = [] while (from &lt;= to) { result.push(from++) } return result}// 2. implement iterable/iterator protocol// for ... of uses interable protocol// [Symbol.iterator]: () =&gt; Iterator// next: () =&gt; {done: bolean, value?: any} function range(from, to) { return { // iterable protocol [Symbol.iterator]() { // iterator protocol return { next() { return { done: from &gt; to, value: from++ } } } } }}// 3. use geneator function to make things simpler// geneator function returns generator which implements iterator protocolfunction range(from, to) { return { // iterable protocol [Symbol.iterator]: function * () { while (from &lt;= to) { yield from++ } } }}// 4. actualy geneator also implements iterable protocolfunction range(from, to) { return (function * () { while (from &lt;= to) { yield from++ } })(from, to)}// 5. maybe just change the entry function?function * range(from, to) { while (from &lt;= to) { yield from++ }}</code></pre>

5 different ways of doing this, most concise with generator functions.

Can you create a range(from, to) which makes following work? for (let num of range(1, 4)) { console.log(num) }// 1// 2// 3// 4 This is a simple one, c…