I've also added the supports for the possible follow ups on cancel, flush, and pending functions.
<pre class="shiki github-dark shaku"><code>/** * @param {Function} func * @param {number} wait * @param {boolean} option.leading * @param {boolean} option.trailing */function throttle(func, wait, option = {leading: true, trailing: true}) { let timer; let lastThis; let lastArgs; let result; wait = +wait || 0; leading = !!option.leading; trailing = !!option.trailing; const leadingEdge = function () { if (leading) { result = invokeFunc() } timer = startTimer(); } const trailingEdge = function () { timer = undefined; if (lastArgs) { if (trailing) { result = invokeFunc(); timer = startTimer(); } } return result; } const invokeFunc = function () { result = func.apply(lastThis, lastArgs); lastThis = undefined; lastArgs = undefined; return result; } const startTimer = function () { return setTimeout(trailingEdge, wait); } const throttled = function () { lastArgs = arguments; lastThis = this; if (timer === undefined) { return leadingEdge(); } return result; } // follow ups: cancel, flush, pending const cancel = function () { clearTimeout(timer); timer = undefined; lastThis = undefined; lastArgs = undefined; } const flush = function () { if (timer !== undefined) { trailingEdge(); } return result; } const pending = () =&gt; timer !== undefined; throttled.cancel = cancel; throttled.flush = flush; throttled.pending = pending; return throttled;}</code></pre>

Simplified version of lodash implementation, with extra supports for cancel, flush, and pending

Google

This is a follow up on 4. implement basic throttle(), please refer to it for detailed explanation. In this problem, you are asked to implement a enhan…