手撕防抖Debounce与节流Throttle

防抖 Debounce：你一直触发，我就一直不执行，等你停下来再执行。
节流 Throttle：你一直触发没关系，但我规定一段时间最多执行一次。

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

/**
 * const log = debounce(console.log, 100);
 * log('Hello'); // cancelled
 * log('Hello'); // cancelled
 * log('Hello'); // Logged at t=100ms
 */

function throttle(fn, delay) {
  let lastTime = 0

  return function (...args) {
    const now = Date.now()

    if (now - lastTime >= delay) {
      fn.apply(this, args)
      lastTime = now
    }
  }
}