<pre class="shiki github-dark shaku"><code>/** * @param {Function} func * @return {Function} */function once(fn) { // your code here let called = false; let result; return function(...args){ if(!called){ called = true; result = fn.call(this,...args); } return result; } }function func(num){ return num;}const onced = once(func);onced(1)onced(2)</code></pre>

Concept	Importance Closures	⭐⭐⭐⭐⭐ Lexical Scope	⭐⭐⭐⭐⭐ Higher-Order Functions	⭐⭐⭐⭐☆ First-Class Functions	⭐⭐⭐⭐☆ Rest Parameters	⭐⭐⭐⭐☆ Spread Operator	⭐

_.once(func) is used to force a function to be called only once, later calls only returns the result of first call. Can you implement your own once()?…