·· function throttle(fn,wait=3000){ let lastTime = Date.now(), timeFlag = null

	return function(...args){
		let current = Date.now()
		
		clearTimeout(timeFlag)
		
		if(current - lastTime >= wait){
			fn.apply(this,args)
			lastTime = current
		}else{
			timeFlag = setTimeout(()=>{
				fn.apply(this,args)
				lastTime = current
			},wait)
		}
	}
}