防抖&节流

防抖

TIP

函数在指定time内只执行一次，time内多次触发，重新计算开始时间。

var debounce = function (fn,time=2000,immediate){
    let timeout = null;
    return function(){
        let context = this;
        let args = arguments;
        let result
        timeout&&clearTimeout(timeout)

        if(immediate) {
            // 立即执行
            if(!timeout) result = fn.apply(context,args);
                timeout = setTimeout(()=>{
                    timeout = null
                },time)
            }else{
             timeout = setTimeout(() => {
                fn.apply(context,args)
            },time)
            return result
        }
    }

    debounce.cancel = function(){
        timeout&&clearTimeout(timeout);
        timeout = null
    }
}

节流

TIP

函数在指定time内只执行一次，同一时间内多次触发，只有一次生效。

var throttle = function (fn,time=1000){
    let timeout
    let start
    return function(){
        const context = this
        const args = arguments
        let cur = +new Date
        if(!start || cur-start>time){
            start = +new Date
            return fn.apply(context,args)
        }
    }
}
var fn = () => {console.log('fn')}
setInterval(throttle(fn),10)