bạn tham khảo nhé:
<!DOCTYPE html><html><body onload="startTime()"><h2>JavaScript Clock</h2><div id="txt"></div><script>function startTime() { const today = new Date(); let h = today.getHours(); let m = today.getMinutes(); let s = today.getSeconds(); m = checkTime(m); s = checkTime(s); document.getElementById('txt').innerHTML = h + ":" + m + ":" + s; setTimeout(startTime, 1000);}function checkTime(i) { if (i < 10) {i = "0" + i}; // add zero in front of numbers < 10 return i;}</script></body></html>
<!DOCTYPE html>
<html>
<body onload="startTime()">
<h2>JavaScript Clock</h2>
<div id="txt"></div>
<script>
function startTime() {
const today = new Date();
let h = today.getHours();
let m = today.getMinutes();
let s = today.getSeconds();
m = checkTime(m);
s = checkTime(s);
document.getElementById('txt').innerHTML = h + ":" + m + ":" + s;
setTimeout(startTime, 1000);
}
function checkTime(i) {
if (i < 10) {i = "0" + i}; // add zero in front of numbers < 10
return i;
</script>
</body>
</html>