Front-end performance optimization - image stabilization and the throttle

What is image stabilization and throttle

• Image stabilization
  so that function for some time after the trigger event and then stop execution
• Throttling
  let function at a fixed frequency trigger

Why shake throttle

When we give a button or move the mouse to add the corresponding event time, if not require real-time response, you can use image stabilization, throttling to optimize the performance of the page
html

     <button id="add">点击加一</button>
     <label id="addLable" for="add"></label>

js

let count = 0;
const add = document.querySelector('#add');
const addLabel = document.querySelector('#addLable');
add.addEventListener('click', () => {
  addLable.innerHTML = ++count;
});

Shake

The principle is to let anti-shake function allows the function to delay execution, if triggered during a new event, cancel the original plan delayed
html

 <button id="add1">防抖加一</button>
 <label id="addLable1" for="add1"></label>

js

let count1 = 0;
const add1 = document.querySelector('#add1');
const addLabel1 = document.querySelector('#addLable1');
let timeout;
const add1Click = function() {
 addLabel1.innerHTML = ++count1;
};
add1.addEventListener('click', () => {
 if (timeout) {
   clearTimeout(timeout);
 }
 timeout = setTimeout(add1Click, 500);
});

More elegant code
to know the rationale behind, you can help us achieve it with lodash tool library, looking more convenient and simple
_.debounce (FUNC, timeout)
lodash official website

let count1 = 0;
const add1 = document.querySelector('#add1');
const addLabel1 = document.querySelector('#addLable1');
let timeout;
const add1Click = function() {
  addLabel1.innerHTML = ++count1;
};
// add1.addEventListener('click', () => {
//   if (timeout) {
//     clearTimeout(timeout);
//   }
//   timeout = setTimeout(add2Click, 500);
// });
add1.addEventListener('click', _.debounce(add1Click, 500));

Throttling

Throttle function within a certain time, only trigger once
html

      <button id="add2">节流加一</button>
      <label id="addLable2" for="add2"></label>

js

let count2 = 0;
const add2 = document.querySelector('#add2');
const addLabel2 = document.querySelector('#addLable2');
const add2Click = function() {
  addLabel2.innerHTML = ++count2;
};
let beAbleClick = true;
add2.addEventListener('click', () => {
  if (!beAbleClick) {
    return;
  }
  setTimeout(() => {
    add2Click();
    beAbleClick = true;
  }, 500);
  beAbleClick = false;
});

More elegantly
same lodash tools have methods available _.throttle (func, timeout)

let count2 = 0;
const add2 = document.querySelector('#add2');
const addLabel2 = document.querySelector('#addLable2');
const add2Click = function() {
  addLabel2.innerHTML = ++count2;
};
// let beAbleClick = true;
// add2.addEventListener('click', () => {
//   if (!beAbleClick) {
//     return;
//   }
//   setTimeout(() => {
//     add2Click();
//     beAbleClick = true;
//   }, 500);
//   beAbleClick = false;
// });
add2.addEventListener('click', _.throttle(add2Click, 500));
``