什么是防抖
在时间触发n秒之后在执行回调函数。如果在n秒之类又被触发,则重新计数
window.onload = function () {
//模拟ajax请求
function ajax(content) {
console.log('ajax request ' + content)
}
function debounce(fun, delay) {
return function (args) {
//获取函数的作用域和变量
let that = this
let _args = args
//每次事件被触发,都会清除当前的timeer,然后重写设置超时调用
clearTimeout(fun.id)
fun.id = setTimeout(function () {
fun.call(that, _args)
}, delay)
}
}
let inputDebounce = document.getElementById('debounce')
let debounceAjax = debounce(ajax, 500)
inputDebounce.addEventListener('keyup', function (e) {
debounceAjax(e.target.value)
})
}
什么是节流
规定在单位时间,在这个单位时间只有一次触发事件的回调函数执行。如果在同一单位时间内某事件触发多次,只有一次生效
window.onload = function () {
//模拟ajax请求
function ajax(content) {
console.log('ajax request ' + content)
}
function throttle(fun, delay) {
let last, deferTimer
return function (args) {
let that = this;
let _args = arguments;
let now = +new Date();
if (last && now < last + delay) {
clearTimeout(deferTimer);
deferTimer = setTimeout(function () {
last = now;
fun.apply(that, _args);
}, delay)
} else {
last = now;
fun.apply(that, _args);
}
}
}
let throttleAjax = throttle(ajax, 1000)
let inputThrottle = document.getElementById('throttle')
inputThrottle.addEventListener('keyup', function (e) {
throttleAjax(e.target.value)
})
}