首先最基础的就是需要准备好node环境，包管理工具。

安装typescript和新建项目

  1. //使用命令行在系统全局安装typescript
  2. npm install typescript -g | yarn add typescript
  4. //创建typescript文件夹
  5. mkdir typescript-demo 
  6. cd typescript-demo
  8. //创建src文件夹
  9. mkdir src
  11. //在src文件夹中创建index.ts文件
  12. touch src/index.ts
  14. //目录初始化（package.json文件） 
  15. npm init
  17. //ts初始化（生成tsconfig.json文件）
  18. tsc --init

接下来就是配置我们的tsconfig.json文件，文件中已生成默认的配置，可以自己配置，我的配置如下：

  1. {
  2.   "compilerOptions": {
  3.     /* Visit https://aka.ms/tsconfig to read more about this file */
  5.     /* Projects */
  6.     // "incremental": true,                              /* Save .tsbuildinfo files to allow for incremental compilation of projects. */
  7.     // "composite": true,                                /* Enable constraints that allow a TypeScript project to be used with project references. */
  8.     // "tsBuildInfoFile": "./.tsbuildinfo",              /* Specify the path to .tsbuildinfo incremental compilation file. */
  9.     // "disableSourceOfProjectReferenceRedirect": true,  /* Disable preferring source files instead of declaration files when referencing composite projects. */
  10.     // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */
  11.     // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
  13.     /* Language and Environment */
  14.     "target": "es5",                                  /* 制定ECMAScript版本为es5 */
  15.     "lib": ["es6", "dom"],                            /* 指定要包含在编译库的文件*/
  16.     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
  17.     "experimentalDecorators": true,                   /* 启用实验性es装饰器 */
  18.     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
  19.     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */
  20.     // "jsxFragmentFactory": "",                         /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
  21.     // "jsxImportSource": "",                            /* Specify module specifier used to import the JSX factory functions when using 'jsx: react-jsx*'. */
  22.     // "reactNamespace": "",                             /* Specify the object invoked for 'createElement'. This only applies when targeting 'react' JSX emit. */
  23.     // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
  24.     // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
  25.     // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
  27.     /* Modules */
  28.     "module": "commonjs",                                /* 指定使用commonjs，amd,system,umd ,es2015 */
  29.     "rootDir": "./",                                  /* 主路径 */
  30.     "moduleResolution": "node",                       /* 选择模块解析策略 */
  31.     // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
  32.     // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
  33.     // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
  34.     "typeRoots": ["node_modules/@types"],                /* Specify multiple folders that act like './node_modules/@types'. */
  35.     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
  36.     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
  37.     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
  38.     // "resolveJsonModule": true,                        /* Enable importing .json files. */
  39.     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
  41.     /* JavaScript Support */
  42.     // "allowJs": true,                                  /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
  43.     // "checkJs": true,                                  /* Enable error reporting in type-checked JavaScript files. */
  44.     // "maxNodeModuleJsDepth": 1,                        /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */
  46.     /* Emit */
  47.     "declaration": true,                              /* 生成相应的.d.ts文件 */
  48.     // "declarationMap": true,                           /* Create sourcemaps for d.ts files. */
  49.     // "emitDeclarationOnly": true,                      /* Only output d.ts files and not JavaScript files. */
  50.     "sourceMap": true,                                /* 把ts编译成js的时候默认生成map文件 */
  51.     // "outFile": "./",                                  /* Specify a file that bundles all outputs into one JavaScript file. If 'declaration' is true, also designates a file that bundles all .d.ts output. */
  52.     "outDir": "./",                                   /* 导出文件夹 */
  53.     "removeComments": true,                           /*删除编译后的所有注释 */
  54.     // "noEmit": true,                                   /* Disable emitting files from a compilation. */
  55.     "importHelpers": true,                            /* 从tslib导入辅助工具函数 */
  56.     // "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types. */
  57.     // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
  58.     // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
  59.     // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
  60.     // "inlineSourceMap": true,                          /* Include sourcemap files inside the emitted JavaScript. */
  61.     // "inlineSources": true,                            /* Include source code in the sourcemaps inside the emitted JavaScript. */
  62.     // "emitBOM": true,                                  /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
  63.     // "newLine": "crlf",                                /* Set the newline character for emitting files. */
  64.     // "stripInternal": true,                            /* Disable emitting declarations that have '@internal' in their JSDoc comments. */
  65.     // "noEmitHelpers": true,                            /* Disable generating custom helper functions like '__extends' in compiled output. */
  66.     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
  67.     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
  68.     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
  69.     // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
  71.     /* Interop Constraints */
  72.     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
  73.     "allowSyntheticDefaultImports": true,             /* 允许从没有设置默认导出的模块默认导入 */
  74.     "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
  75.     // "preserveSymlinks": true,                         /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
  76.     "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
  78.     /* Type Checking */
  79.     "strict": true,                                      /* 启用所有严格类型检查选项 */
  80.     "noImplicitAny": true,                            /* 在表达式和声明上有隐含any类型时报错 */
  81.     // "strictNullChecks": true,                         /* When type checking, take into account 'null' and 'undefined'. */
  82.     // "strictFunctionTypes": true,                      /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
  83.     // "strictBindCallApply": true,                      /* Check that the arguments for 'bind', 'call', and 'apply' methods match the original function. */
  84.     // "strictPropertyInitialization": true,             /* Check for class properties that are declared but not set in the constructor. */
  85.     // "noImplicitThis": true,                           /* Enable error reporting when 'this' is given the type 'any'. */
  86.     // "useUnknownInCatchVariables": true,               /* Default catch clause variables as 'unknown' instead of 'any'. */
  87.     "alwaysStrict": true,                             /* 以严格模式检查模块，并在每个文件加入'use strict' */
  88.     // "noUnusedLocals": true,                           /* Enable error reporting when local variables aren't read. */
  89.     // "noUnusedParameters": true,                       /* Raise an error when a function parameter isn't read. */
  90.     // "exactOptionalPropertyTypes": true,               /* Interpret optional property types as written, rather than adding 'undefined'. */
  91.     "noImplicitReturns": true,                        /* 不是函数所有返回路径都有返回值时报错 */
  92.     // "noFallthroughCasesInSwitch": true,               /* Enable error reporting for fallthrough cases in switch statements. */
  93.     // "noUncheckedIndexedAccess": true,                 /* Add 'undefined' to a type when accessed using an index. */
  94.     // "noImplicitOverride": true,                       /* Ensure overriding members in derived classes are marked with an override modifier. */
  95.     // "noPropertyAccessFromIndexSignature": true,       /* Enforces using indexed accessors for keys declared using an indexed type. */
  96.     // "allowUnusedLabels": true,                        /* Disable error reporting for unused labels. */
  97.     // "allowUnreachableCode": true,                     /* Disable error reporting for unreachable code. */
  99.     /* Completeness */
  100.     // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
  101.     "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  102.   },
  103.   "include": [                                  // 需要编译的ts文件一个*表示文件匹配**表示忽略文件的深度问题
  104.     "./src/**/*.ts"
  105.   ],
  106.   "exclude": [                                   //排除不需要打包的文件
  107.     "node_modules",
  108.     "dist",
  109.     "**/*.test.ts",
  110.   ]
  111. }

里面我用到的都做了中文标注，其他暂时没有翻译成中文，大家自行理解。
然后我们接着在package.json文件中加入我们自己的命令：

  1. {
  2.   "name": "ts-study",
  3.   "version": "1.0.0",
  4.   "description": "",
  5.   "main": "src/index.ts",
  6.     //这里是加入的命令
  7.   "scripts": {
  8.     "build": "tsc",
  9.     "build:w": "tsc -w"
  10.   },
  11.   "author": "",
  12.   "license": "ISC",
  13.   "devDependencies": {
  14.     "typescript ": "^3.6.4"
  15.   },
  16.     //以下是我配置自己的eslint使用的相关插件，大家不一定需要下载，后面会逐渐整理关于eslint配置文章
  17.   "dependencies": {
  18.     "@typescript-eslint/eslint-plugin": "^5.28.0",
  19.     "@typescript-eslint/parser": "^5.28.0",
  20.     "eslint": "^8.17.0",
  21.     "eslint-config-standard": "^17.0.0",
  22.     "eslint-plugin-import": "^2.26.0",
  23.     "eslint-plugin-node": "^11.1.0",
  24.     "eslint-plugin-promise": "^6.0.0"
  25.   }
  26. }

开始尝试吧！

  1. function statementTest(value) {
  2.   return value;
  3. }
  5. const greet = 'Hello World';
  6. /*由下图可见，当我们在tsconfig.json文件中配置了开启严格模式之后，有隐含
  7. 的any类型是会报错的，当然也可以不开启，但是若ts中any类型泛滥，typescript
  8. 也就变成了anyscript，失去了我们使用ts的初衷。*/

image.png
我们在上面代码的基础上，做以下修改：

  1. function statementTest(value:number) {
  2.   return value;
  3. }
  5. const greet = 'Hello World';
  6. /*加上类型声明，完美解决，可以看到ts自动推导出了函数返回值为number*/

image.png
至此为止，我们完成了ts的第一行代码编写。