5种使JavaScript代码库更干净的方法

共 4620字,需浏览 10分钟

 ·

2021-05-16 01:42

文 | https://betterprogramming.pub/5-practices-to-make-your-javascript-code-base-cleaner-611300dfe088
翻译 | 杨小二

JavaScript无处不在,从PC端到移动设备端,甚至是后端,都在使用JavaScript。
在本文中,我将尝试一些可用来使代码看起来更简洁的实践方案。

1、使用默认参数代替短路或条件

默认参数通常比短路更干净。
function SomeMethod(paramThatCanBeUndefined) {
const localValue = paramThatCanBeUndefined || "Default Value"; console.log(localValue) // ...}SomeMethod() // Default ValueSomeMethod("SomeValue") // SomeValue

尝试以下方法:

function SomeMethod(  console.log(paramThatCanBeUndefined)  // ...}SomeMethod() // Default ValueSomeMethod("SomeValue") // SomeValue

声明:Falsy值,如'',"",false,null,0,和NaN将不会被默认值替代:

function SomeMethod(paramThatCanBeUndefined = "Default Value") {          console.log(paramThatCanBeUndefined)    // ...}SomeMethod(null) // will not Default Value, will null InsteadSomeMethod("SomeValue") // SomeValue

2、处理多个条件

const conditions = ["Condition 2","Condition String2"];someFunction(str){  if(str.includes("someValue1") || str.includes("someValue2")){    return true  }else{    return false  }}

一种更干净的方法是:

someFunction(str){   const conditions = ["someValue1","someValue2"];   return conditions.some(condition=>str.includes(condition));}

3、用动态键值对替换开关(即对象文字)

开关版本(或将开关替换为if / else):

const UserRole = {  ADMIN: "Admin",  GENERAL_USER: "GeneralUser",  SUPER_ADMIN: "SuperAdmin",};function getRoute(userRole = "default role"){

switch(userRole){ case UserRole.ADMIN: return "/admin" case UserRole.GENERAL_USER: return "/GENERAL_USER" case UserRole.SUPER_ADMIN: return "/superadmin" default: return "/" }
}console.log(getRoute(UserRole.ADMIN)) // return "/admin"console.log(getRoute("Anything")) // return Default pathconsole.log(getRoute()) // return Default pathconsole.log(getRoute(null)) // return Default path
// More cases if new arrive// You can think if else instead of switch

动态键值对版本:

const UserRole = {   ADMIN: "Admin",   GENERAL_USER: "GeneralUser",   SUPER_ADMIN: "SuperAdmin",};function getRoute(userRole = "default role"){ const appRoute = {  [UserRole.ADMIN]: "/admin",  [UserRole.GENERAL_USER]: "/user",  [UserRole.SUPER_ADMIN]: "/superadmin" }; return appRoute[userRole] || "Default path";}console.log(getRoute(UserRole.ADMIN)) // return "/admin"console.log(getRoute("Anything")) // return Default pathconsole.log(getRoute()) // return Default pathconsole.log(getRoute(null)) // return Default path// No more switch/if-else here.// Easy to Further expansion

4、避免过多的函数参数

function myFunction(employeeName,jobTitle,yrExp,majorExp){ return `${employeeName} is working as ${jobTitle} with ${yrExp}    years of experience in ${majorExp}`}//output be like John is working as Project Manager with 12 year of experience in Project Management// you can call it viaconsole.log(myFunction("John","Project Manager",12,"Project Management"))//    ***** PROBLEMS ARE *****// Violation of 'clean code' principle// Parameter sequencing is important// Unused Params warning if not used// Testing need to consider a lot of edge cases.

这是一种更清洁的方法:

function myFunction({employeeName,jobTitle,yrExp,majorExp}){ return `${employeeName} is working as ${jobTitle} with ${yrExp} years of experience in ${majorExp}`}//output be like John is working as Project Manager with 12 year of experience in Project Management// you can call it viaconst mockTechPeople = {  employeeName:"John",  jobTitle:"Project Manager",  yrExp:12,  majorExp:"Project Management"}console.log(myFunction(mockTechPeople))// ES2015/ES6 destructuring syntax is in action// map your desired value to variable you need.

5、使用Object.assign设置默认对象

这看起来很繁琐:

const someObject = { title: null, subTitle: "Subtitle", buttonColor: null, disabled: true};function createOption(someObject) { someObject.title = someObject.title || "Default Title"; someObject.subTitle = someObject.subTitle || "Default Subtitle"; someObject.buttonColor = someObject.buttonColor || "blue"; someObject.disabled = someObject.disabled !== undefined ?  someObject.disabled : true; return someObject}console.log(createOption(someObject));
// Output be like // {title: 'Default Title', subTitle: 'Subtitle', buttonColor: 'blue', disabled: true}

这种方法看起来更好:

const someObject = {  title: null,  subTitle: "Subtitle",  buttonColor: null,  disabled: true }; function creteOption(someObject) {  const newObject = Object.assign({   title: "Default Title",   subTitle: "Default Subtitle",   buttonColor: "blue",   disabled: true },someObject) return newObject } console.log(creteOption(someObject));

最后,谢谢你的阅读,祝编程愉快!

学习更多技能

请点击下方公众号


浏览 11
点赞
评论
收藏
分享

手机扫一扫分享

分享
举报
评论
图片
表情
推荐
点赞
评论
收藏
分享

手机扫一扫分享

分享
举报