【编程】八股文算法题大赏

防抖节流

// 💊点  每次都返回 一个函数

function Denounce(fn, wait = 500) {
  let timer = null;
  return function () {
    // 每次都clearTime
    if (timer) clearTimeout(timer);
    timer = setTimeout(() => {
      timer = null;
      fn.apply(this, arguments);
    }, wait);
  };
}

function Throtte(fn, wait = 500) {
  let timer = null;
  return function () {
    // 存在就拉闸 不然执行后续的
    if (timer) return;
    timer = setTimeout(() => {
      timer = null;
      fn.apply(this, arguments);
    }, wait);
  };
}

call bind apply

Function.prototype.myApply = function (ctx = globalThis) {
  ctx.fn = this;
  const args = [...arguments].slice(1);
  const res = ctx.fn(args);
  delete ctx.fn;
  return res;
};

Function.prototype.myCall = function (ctx = globalThis) {
  // 如果怕冲突 用 const fn = Symbol(ctx)
  ctx.fn = this;
  const args = [...arguments].slice(1);
  const res = ctx.fn(...args);
  delete ctx.fn;
  return res;
};

Function.prototype.myBind = function (ctx = globalThis) {
  const that = this;
  const args = [...arguments].slice(1);
  return function () {
    return that.apply(ctx, [...arguments, ...args]);
  };
};