易读、易复用、易重构的 JavaScript 代码规范
1.变量命名规范有意义
Bad:
const yyyymmdstr = moment().format("YYYY/MM/DD");
Good:
const currentDate = moment().format("YYYY/MM/DD");
2. 给变量定义名字
Bad: // What the heck is 86400000 for?
setTimeout(blastOff, 86400000);
Good: // Declare them as capitalized named constants.
const MILLISECONDS_IN_A_DAY = 86_400_000; setTimeout(blastOff, MILLISECONDS_IN_A_DAY);
3.函数的变量定义初始值
Bad:
function createMicrobrewery(name) {
const breweryName = name || "Hipster Brew Co.";
// ...
}
Good:
function createMicrobrewery(name = "Hipster Brew Co.") {
// ...
}
4.函数的形参过多时候，用对象代替多个参数
Bad:
function createMenu(title, body, buttonText, cancellable) {
// ...
}
createMenu("Foo", "Bar", "Baz", true);
Good:
function createMenu({ title, body, buttonText, cancellable }) {
// ...
}
createMenu({
title: "Foo",
body: "Bar",
buttonText: "Baz",
cancellable: true
});
5.函数应该只做一件事情
Bad:
function emailClients(clients) {
clients.forEach(client => {
const clientRecord = database.lookup(client);
if (clientRecord.isActive()) {
email(client);
}
});
}
Good:
function emailActiveClients(clients) {
clients.filter(isActiveClient).forEach(email);
}
function isActiveClient(client) {
const clientRecord = database.lookup(client);
return clientRecord.isActive();
}
6.函数名称应该说明其作用
Bad:
function addToDate(date, month) {
// ...
}
const date = new Date();
// It's hard to tell from the function name what is added
addToDate(date, 1);
Good:
function addMonthToDate(month, date) {
// ...
}
const date = new Date();
addMonthToDate(1, date)
7.使用Object.assign拷贝对象
Good:
const menuConfig = {
title: "Order",
// User did not include 'body' key
buttonText: "Send",
cancellable: true
};
function createMenu(config) {
config = Object.assign(
{
title: "Foo",
body: "Bar",
buttonText: "Baz",
cancellable: true
},
config
);
// config now equals: {title: "Order", body: "Bar", buttonText: "Send", cancellable: true}
// ...
}
createMenu(menuConfig);
8.开闭原则
对扩展开放，对修改关闭；
面向对象开发
9.函数的继承
class Animal {
constructor(age) {
this.age = age;
}
move() {
/* ... */
}
}
class Mammal extends Animal {
constructor(age, furColor) {
super(age);
this.furColor = furColor;
}
liveBirth() {
/* ... */
}
}
class Human extends Mammal {
constructor(age, furColor, languageSpoken) {
super(age, furColor);
this.languageSpoken = languageSpoken;
}
speak() {
/* ... */
}
}
10 链式编程 在每个函数的结尾返回this即可
（这种模式在JavaScript中非常有用，您可以在jQuery和Lodash等许多库中看到它。它使您的代码更具表现力，并且不再那么冗长。出于这个原因，我说，使用方法链接并查看代码的干净程度。在类函数中，只需this在每个函数的末尾返回即可，然后可以将更多的类方法链接到该函数上。）
class Car {
constructor(make, model, color) {
this.make = make;
this.model = model;
this.color = color;
}
setMake(make) {
this.make = make;
// NOTE: Returning this for chaining
return this;
}
setModel(model) {
this.model = model;
// NOTE: Returning this for chaining
return this;
}
setColor(color) {
this.color = color;
// NOTE: Returning this for chaining
return this;
}
save() {
console.log(this.make, this.model, this.color);
// NOTE: Returning this for chaining
return this;
}
}
const car = new Car("Ford", "F-150", "red").setColor("pink").save();
11.async/await 来处理异步编程
参考地址来源 ：https://github.com/ryanmcdermott/clean-code-javascript