Timing Events
សេចក្តីផ្តើម
Timing Events អនុញ្ញាតឱ្យ JavaScript execute code នៅពេលកំណត់។ Methods ពីរគឺ setTimeout() និង setInterval()។
Timing Methods
Method | ការពិពណ៌នា | ឧទាហរណ៍ |
---|---|---|
setTimeout() | Execute once after delay | setTimeout(fn, 1000) |
clearTimeout() | Cancel setTimeout | clearTimeout(id) |
setInterval() | Execute repeatedly | setInterval(fn, 1000) |
clearInterval() | Cancel setInterval | clearInterval(id) |
setTimeout()
setTimeout(function() {
console.log("Executed after 3 seconds");
}, 3000);
Execute code ម្តង បន្ទាប់ពីពេលកំណត់
clearTimeout()
let timeoutId = setTimeout(fn, 3000);
clearTimeout(timeoutId); // Cancel
Cancel setTimeout មុនពេលវា execute
setInterval()
setInterval(function() {
console.log("Executed every 2 seconds");
}, 2000);
Execute code ម្តងហើយម្តងទៀត
clearInterval()
let intervalId = setInterval(fn, 1000);
clearInterval(intervalId); // Stop
ឈប់ setInterval
Countdown Timer
let count = 10;
let timer = setInterval(function() {
console.log(count--);
if (count < 0) clearInterval(timer);
}, 1000);
បង្កើត countdown timer
Clock Example
setInterval(function() {
let now = new Date();
console.log(now.toLocaleTimeString());
}, 1000);
បង្ហាញពេលវេលា real-time
Best Practices
- តែងតែ clear timers នៅពេលមិនត្រូវការ
- ប្រើ arrow functions សម្រាប់ cleaner code
- ជៀសវាង nested timers
- ពិចារណា requestAnimationFrame() សម្រាប់ animations
សង្ខេប
- setTimeout() - Execute once after delay
- clearTimeout() - Cancel setTimeout
- setInterval() - Execute repeatedly
- clearInterval() - Stop setInterval
- Time ជា milliseconds (1000ms = 1 second)