js实现短信验证码倒计时

// 倒计时
function countDown() {
	// 是否显示验证码按钮
	let show = true
	// 初始值
	let count = 0
	// 定时器
	let timer = null
	// 禁止重复点击
	if (!show) return
	// 设置倒计时为60s
	const TIME_COUNT = 60
	if (!timer) {
		count = TIME_COUNT
		show = false
		timer = setInterval(() => {
			if (count > 0 && count <= TIME_COUNT) {
				count--
				// TODO: 执行倒计时
			} else {
				show = true
				clearInterval(timer)
				timer = null
				// TODO: 倒计时结束
			}
		}, 1000)
	}
}