一. 使用箭头函数简化函数定义
// 传统函数定义 function add(a, b) { return a + b; } // 堆代码 duidaima.com // 箭头函数简化 const add = (a, b) = >a + b;二. 使用解构赋值简化变量声明
// 传统变量声明 const firstName = person.firstName; const lastName = person.lastName; // 解构赋值简化 const { firstName, lastName } = person;三. 使用模板字面量进行字符串拼接
// 传统字符串拼接 const greeting = 'Hello, ' + name + '!'; // 模板字面量简化 const greeting = `Hello, ${name}!`;四. 使用展开运算符进行数组和对象操作
// 合并数组 const combined = [...array1, ...array2]; // 复制对象 const clone = { ...original };五. 使用数组的高阶方法简化循环和数据操作
// 遍历数组并返回新数组 const doubled = numbers.map(num => num * 2); // 过滤数组 const evens = numbers.filter(num => num % 2 === 0);六. 使用条件运算符简化条件判断
// 传统条件判断 let message; if (isSuccess) { message = 'Operation successful'; } else { message = 'Operation failed'; } // 条件运算符简化 const message = isSuccess ? 'Operation successful' : 'Operation failed';七. 使用对象解构和默认参数简化函数参数
// 传统参数设置默认值 function greet(name) { const finalName = name || 'Guest'; console.log(`Hello, ${finalName}!`); } // 对象解构和默认参数简化 function greet({ name = 'Guest' }) { console.log(`Hello, ${name}!`); }八. 使用函数式编程概念如纯函数和函数组合
// 纯函数 function add(a, b) { return a + b; } // 函数组合 const multiplyByTwo = value => value * 2; const addFive = value => value + 5; const result = addFive(multiplyByTwo(3));九. 使用对象字面量简化对象的创建和定义
// 传统对象创建 const person = { firstName: 'John', lastName: 'Doe', age: 30, }; // 对象字面量简化 const firstName = 'John'; const lastName = 'Doe'; const age = 30; const person = { firstName, lastName, age };十. 使用适当的命名和注释来提高代码可读性
// 不好的 const x = 10; // 设置x的值为10 function a(b) { return b * 2; // 返回b的两倍 } // 好的 const speed = 10; // 设置速度为10 function double(value) { return value * 2; // 返回输入值的两倍十一. 优雅的写条件判断代码
<view>{{status===1?'成功': status===2 ? '失败' : status===3 ? '进行中' : '未开始' }}</view>大概是这样的,具体的项目代码不好放在这里,小伙伴们意会就行。复杂逻辑推荐使用对象Map写法,符合人脑的逻辑,可读性高,看着舒服~~~
let txt = ''; if (falg) { txt = "成功" } else { txt = "失败" }2,三元运算符
let txt = flag ? "成功" : "失败";3,多个if else
// param {status} status 活动状态:1:成功 2:失败 3:进行中 4:未开始 let txt = ''; if (status == 1) { txt = "成功"; } else if (status == 2) { txt = "失败"; } else if (status == 3) { txt = "进行中"; } else { txt = "未开始"; }4,switch case
let txt = ''; switch (status) { case 1: txt = "成功"; break; case 2: txt = "成功"; break; case 3: txt = "进行中"; break; default: txt = "未开始"; }5,对象写法
const statusMap = { 1: "成功", 2: "失败", 3: "进行中", 4: "未开始" } //调用直接 statusMapp[status]7,Map写法
const actions = new Map([ [1, "成功"], [2, "失败"], [3, "进行中"], [4, "未开始"] ]) // 调用直接 actions.get(status)十二. 封装条件语句
// 不好的 if (fsm.state === 'fetching' && isEmpty(listNode)) { // ... } // 好的 shouldShowSpinner(fsm, listNode){ return fsm.state === 'fetching' && isEmpty(listNode) } if(shouldShowSpinner(fsm, listNode)){ //...doSomething }十三. 函数应该只做一件事
// 不好的 function createFile(name, temp) { if (temp) { fs.create(`./temp/${name}`); } else { fs.create(name); } } // 好的 function createFile(name) { fs.create(name); } function createTempFile(name) { createFile(`./temp/${name}`) }再来一个栗子
// 不好的 function emailClients(clients) { clients.forEach((client) => { const clientRecord = database.lookup(client); if (clientRecord.isActive()) { email(client); } }); } // 好的 function emailClients(clients) { clients .filter(isClientRecord) .forEach(email) } function isClientRecord(client) { const clientRecord = database.lookup(client); return clientRecord.isActive() }上面不好的栗子一眼看过去是不是感觉一堆代码在那,一时半会甚至不想去看了。好的栗子,是不是逻辑很清晰,易读。
// 不好的 const menuConfig = { title: null, body: 'Bar', buttonText: null, cancellable: true }; function createMenu(config) { config.title = config.title || 'Foo'; config.body = config.body || 'Bar'; config.buttonText = config.buttonText || 'Baz'; config.cancellable = config.cancellable === undefined ? config.cancellable : true; } createMenu(menuConfig); // 好的 const menuConfig = { title: 'Order', buttonText: 'Send', cancellable: true }; function createMenu(config) { Object.assign({ title: 'Foo', body: 'Bar', buttonText: 'Baz', cancellable: true }, config) } createMenu(menuConfig);十五. 函数参数两个以下最好
// 不好的 function createMenu(title, body, buttonText, cancellable) { // ... } // 好的 const menuConfig = { title: 'Foo', body: 'Bar', buttonText: 'Baz', cancellable: true }; function createMenu(config){ // ... } createMenu(menuConfig)十六. 使用解释性的变量
// 不好的 const address = 'One Infinite Loop, Cupertino 95014'; const cityZipCodeRegex = /^[^,\\]+[,\\\s]+(.+?)\s*(\d{5})?$/; saveCityZipCode(address.match(cityZipCodeRegex)[1], address.match(cityZipCodeRegex)[2]); // 好的 const address = 'One Infinite Loop, Cupertino 95014'; const cityZipCodeRegex = /^[^,\\]+[,\\\s]+(.+?)\s*(\d{5})?$/; cosnt [, city, zipCode] = address.match(cityZipCodeRegex) || []; saveCityZipCode(city, zipCode)想对类中的属性进行更多自定义取/增/改的操作时,使用set/get
Object.defineProperty(data1,'age',{ set:function(newAge){ console.log(this.name+'现在'+newAge+'岁') }, get:function(){ return 18; } })是一个意思,赋值的时候set会被触发,取值的时候get会被触发。
class BankAccount { constructor(balance = 1000) { this._balance = balance; } // It doesn't have to be prefixed with `get` or `set` to be a //getter/setter set balance(amount) { console.log('set') if (verifyIfAmountCanBeSetted(amount)) { this._balance = amount; } } get balance() { console.log('get') return this._balance; } verifyIfAmountCanBeSetted(val) { // ... } } const bankAccount = new BankAccount(); // Buy shoes... bankAccount.balance -= 100; // Get balance let balance = bankAccount.balance;十七. 让对象拥有私有成员-通过闭包来实现
// 不好的 const Employee = function(name) { this.name = name; }; Employee.prototype.getName = function getName() { return this.name; }; const employee = new Employee('John Doe'); console.log(`Employee name: ${employee.getName()}`); // Employee name: John Doe delete employee.name; console.log(`Employee name: ${employee.getName()}`); // Employee name: undefined // 好的 const Employee = function(name){ this.getName = function(){ return name } } const employee = new Employee('John Doe'); console.log(`Employee name: ${employee.getName()}`); // Employee name: John Doe delete employee.name; console.log(`Employee name: ${employee.getName()}`); // Employee name: undefined第一个示例
// 不好的 class Car { constructor() { this.make = 'Honda'; this.model = 'Accord'; this.color = 'white'; } setMake(make) { this.make = make; } save() { console.log(this.make, this.model, this.color); } } const car = new Car(); car.setMake('Ford'); car.save(); // 好的 class Car { constructor() { this.make = 'Honda'; this.model = 'Accord'; this.color = 'white'; } setMake(make) { this.make = make; // NOTE: return this是为了用链式写法 return this; } save() { console.log(this.make, this.model, this.color); // NOTE:return this是为了用链式写法 return this; } } const car = new Car() .setMake('Ford') .save();看完上面的这么多栗子,小伙伴的思路是不是清晰了很多,在你们的项目里练练手吧。