// 节流
var input = document.getElementById('input');
function throttle(f,ms) {
var prev = new Date();
return function() {
let now = new Date();
if(now - prev > ms) {
f();
prev = new Date()
}
}
}
function change() {
console.log(input.value)
}
input.addEventListener('keyup',throttle(change,1500) )
<input id='input'>