防抖和节流
防抖
防抖是函数在一段时间内只执行一次，如果再次调用则重新计时
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| function debounce(fn, delay) {
let timeOut;
return function (...args) {
clearTimeout(timeOut);
timeOut = setTimeout(function() {
fn.apply(this, args)
}, delay)
}
}
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节流
在一个单位时间内函数只能触发一次， 多次触发也只有一次生效
实现
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| function throttle(fn, delay) {
let later, timer
return function (...args) {
clearTimeout(timer)
const now = new Date().getTime()
if (later && now < later + delay) {
timer = setTimeout(function () {
later = now
fn.apply(this, args)
}, delay)
} else {
later = now
fn.apply(this, args)
}
}
}
|