倒计时计时器-在变量过期时隐藏它们

Question

要想获得倒计时计时器的帮助，我必须在特定时间向容器显示页面。我想要"；天"小时"分钟"；当它们达到零时消失。

有人能帮忙吗？

<h3 id="demo"></h3>
<script>
// Set the date we're counting down to
var countDownDate = new Date("1/21/2022 11:00:00").getTime();
// Update the count down every 1 second
var x = setInterval(function() {
// Get today's date and time
var now = new Date().getTime();

// Find the distance between now and the count down date
var distance = countDownDate - now;

// Time calculations for days, hours, minutes and seconds
var days = Math.floor(distance / (1000 * 60 * 60 * 24)); 
var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
var seconds = Math.floor((distance % (1000 * 60)) / 1000);

// Output the result in an element with id="demo"
document.getElementById("demo").innerHTML = days + " day " + hours + " hours " +  minutes + " min " + seconds + " sec ";

// If the count down is over, write some text 
if (distance < 0) {
clearInterval(x);
document.getElementById("demo").innerHTML = "Reserve Tickets";
}
}, 1000);
</script> 

Answer 1

仅当距离>0

<h3 id="demo"></h3>
<script>
// Set the date we're counting down to
var countDownDate = new Date("1/21/2022 11:00:00").getTime();
// Update the count down every 1 second
var x = setInterval(function() {
// Get today's date and time
let now = new Date().getTime();

// Find the distance between now and the count down date
let distance = countDownDate - now;

// If the count down is over, write some text 
if (distance >= 0) {
// Time calculations for days, hours, minutes and seconds
let days = Math.floor(distance / (1000 * 60 * 60 * 24)); 
let hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
let minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
let seconds = Math.floor((distance % (1000 * 60)) / 1000);
// Output the result in an element with id="demo"
document.getElementById("demo").innerHTML = days + " day " + hours + " hours " +  minutes + " min " + seconds + " sec ";
} else {
clearInterval(x);
document.getElementById("demo").innerHTML = "Reserve Tickets";
}
}, 1000);
</script>