2627-debounce.js

/**
 * 2627. Debounce
 * https://leetcode.com/problems/debounce/
 * Difficulty: Medium
 *
 * Given a function fn and a time in milliseconds t, return a debounced version of that function.
 *
 * A debounced function is a function whose execution is delayed by t milliseconds and whose
 * execution is cancelled if it is called again within that window of time. The debounced
 * function should also receive the passed parameters.
 *
 * For example, let's say t = 50ms, and the function was called at 30ms, 60ms, and 100ms.
 *
 * The first 2 function calls would be cancelled, and the 3rd function call would be executed
 * at 150ms.
 *
 * If instead t = 35ms, The 1st call would be cancelled, the 2nd would be executed at 95ms,
 * and the 3rd would be executed at 135ms.
 */

/**
 * @param {Function} fn
 * @param {number} t milliseconds
 * @return {Function}
 */
var debounce = function(fn, t) {
  let timer;
  return (...args) => {
    clearTimeout(timer);
    timer = setTimeout(() => fn(...args), t);
  };
};