Cocos Creator
推荐编码规范
下面是 Cocos Creator 开发团队使用的编码规范,收录在手册里以供游戏开发者和工具开发者参考。
命名规范
当我们为变量,函数和实例命名时, 使用 camelCase 命名法。
ts// bad const FOOBar = {}; const foo_bar = {}; function FOOBar () {} // good const fooBar = {}; function fooBar () {}
当变量、函数和实例命名涉及到缩写时,缩写在开头全部小写,在后续单词中,则全部大写。
ts// bad const Id = 0; const iD = 0; function requireId () {} // good const id = 0; const uuid = ''; function requireID () {} class AssetUUID {}
当我们为类或者模块命名时,使用 PascalCase 命名法。
ts// bad const foobar = cc.Class({ foo: 'foo', bar: 'bar', }); const foobar = require('foo-bar'); // good const FooBar = cc.Class({ foo: 'foo', bar: 'bar', }); const FooBar = require('foo-bar');
推荐使用全大写加下划线来命名“常量”。
ts// bad const PRIVATE_VARIABLE = 'should not be unnecessarily uppercased within a file'; // bad var THING_TO_BE_CHANGED = 'should obviously not be uppercased'; // bad let REASSIGNABLE_VARIABLE = 'do not use let with uppercase variables'; // --- // allowed but does not supply semantic value export const apiKey = 'SOMEKEY'; // better in most cases export const API_KEY = 'SOMEKEY'; // --- // bad - unnecessarily uppercases key while adding no semantic value export const MAPPING = { KEY: 'value' }; // good export const Type = { SIMPLE: 'value' };
使用前置下划线
_
当我们为私有属性命名ts// bad this.__firstName__ = 'foobar'; this.firstName_ = 'foobar'; // good this._firstName = 'foobar';
文件名我们采用 dash 命名法
bash// bad fooBar.js FooBar.js // good foo-bar.js
语法规范
当类的属性声明没有初始化式的时候,应当声明 declare,否则可能面临性能问题。详情请参考 Issue
typescript// bad class A { public a: number; constructor (a : number) { // 相当于此处还有一句 this.a = void 0; // 注意可能面临性能问题! this.a = a; } } // good class A { public a: number = 0; // Ok. constructor (a : number) { // 相当于此处还有一句 this.a = 0; // 但不会引起大的性能问题 this.a = a; } } // best class A { public declare a: number; public b: undefined | object; // OK: b 未在构造函数中二次赋值 public declare c: object | null; constructor (a: number, c: object) { this.a = a; this.c = c; } }
使用
Object.create(null)
创建一个字典ts// bad const map = new Object(); // bad const map = {}; // good const map = Object.create(null);
使用
[]
创建一个数组ts// bad const array = new Array(); // good const array = [];
尽可能在 TypeScript 代码中使用单引号
''
来定义 stringts// bad const str = "Hello World"; // good const str = 'Hello World';
多行 string 定义时, 尽可能使用
+
定义ts// bad const errorMessage = 'This is a super long error that was thrown because of Batman. When you stop to think about how Batman had anything to do with this, you would get nowhere fast.'; // bad const errorMessage = 'This is a super long error that was thrown because \ of Batman. When you stop to think about how Batman had anything to do \ with this, you would get nowhere \ fast.'; // good const errorMessage = 'This is a super long error that was thrown because ' + 'of Batman. When you stop to think about how Batman had anything to do ' + 'with this, you would get nowhere fast.';
使用
===
和!==
而不是==
和!=
书写规范
根据个人习惯, 和原代码作者格式, 选择 4 个空格或者 2 个空格作为缩进
ts// bad function () { ∙const name; } // very bad function () { ∙∙<tab>∙∙const name; } // good function () { ∙∙const name; } // good function () { ∙∙∙∙const name; }
行尾不要留有空格,文件底部请留一个空行
js// bad function () {∙ ∙∙∙∙const name;∙ } /* EOF */ // good function () { ∙∙∙∙const name; } /* EOF */
语句结尾请加
;
js// bad proto.foo = function () { } // good proto.foo = function () { }; // bad function foo () { return 'test' } // very bad // returns `undefined` instead of the value on the next line, // always happens when `return` is on a line by itself because of Automatic Semicolon Insertion! function foo () { return 'test' } // good function foo () { return 'test'; } // bad function foo () { }; // good,这里不是语句结尾 function foo () { }
尽可能将
{
和表达式放在同一行ts// bad if ( isFoobar ) { } // good if ( isFoobar ) { } // bad function foobar () { } // good function foobar () { } // bad const obj = { foo: 'foo', bar: 'bar', } // good const obj = { foo: 'foo', bar: 'bar', }
在
{
前请空一格js// bad if (isJedi){ fight(); } else{ escape(); } // good if (isJedi) { fight(); } else { escape(); } // bad dog.set('attr',{ age: '1 year', breed: 'Bernese Mountain Dog', }); // good dog.set('attr', { age: '1 year', breed: 'Bernese Mountain Dog', });
在逻辑状态表达式 (
if
,else
,while
,switch
) 后请空一格js// bad if(isJedi) { fight (); } else{ escape(); } // good if (isJedi) { fight(); } else { escape(); }
二元、三元运算符的左右请空一格
js// bad const x=y+5; const left = rotated? y: x; // good const x = y + 5; const left = rotated ? y : x; // bad for (let i=0; i< 10; i++) { } // good for (let i = 0; i < 10; i++) { }
一些函数的声明方式
js// bad const test = function () { console.log('test'); }; // good function test () { console.log('test'); } // bad function test () { console.log('test'); }; // good function test () { console.log('test'); } // bad function divisibleFunction () { return DEBUG ? 'foo' : 'bar'; } // best const divisibleFunction = DEBUG ? function () { return 'foo'; } : function () { return 'bar'; }; // bad function test(){ } // good function test () { } // bad const obj = { foo: function () { } }; // good const obj = { foo () { } }; // bad array.map(x=>x + 1); array.map(x => { return x + 1; }); // good array.map(x => x + 1);
在 Block 定义之间请空一行
js// bad if (foo) { return bar; } return baz; // good if (foo) { return bar; } return baz; // bad const obj = { x: 0, y: 0, foo () { }, bar () { }, }; return obj; // good const obj = { x: 0, y: 0, foo () { }, bar () { }, }; return obj;
不要使用前置逗号定义
ts// bad const story = [ once , upon , aTime ]; // good const story = [ once, upon, aTime, ]; // bad const hero = { firstName: 'Ada' , lastName: 'Lovelace' , birthYear: 1815 , superPower: 'computers' }; // good const hero = { firstName: 'Ada', lastName: 'Lovelace', birthYear: 1815, superPower: 'computers', };
单行注释请在斜杠后面加一个空格
js//bad // good
多行注释写法
js/* * good */
需要导出到 API 文档的多行注释写法
js/** * good */
除了多语言 API 注释以外,代码中不允许写中文注释
js// bad // 中文注释不利于非中文开发者阅读代码 // good // Please write all in file comments in English