一、安裝環境與配置
1、命令行安裝
npm i -g typescript
2、快捷打開Vs Code編輯器
創建一個項目文件夾，在該文件夾下打開命令行工具，使用code .命令快速打開編輯器（如果計算機提示沒有這個命令，請查找到編輯器安裝目錄bin文件夾下，複製地址。到系統的環境變量下Path，編輯，在前面加上;，粘貼進去就好了）。
3、運行typesript以及同步typesript與js轉換
我們在項目文件夾下創建一個名叫demo1.ts文件。這就是我們學習typesript的起點，要記住typesript需要轉換成js文件纔可以被瀏覽器識別，所以需要運行命令：
tsc demo1.ts
這樣就會在文件夾下生成一個名叫demo1.js文件。是不是感覺每次寫完都要運行命令很煩，所以我們推薦使用Vs code編輯器，讓你每次編寫ts的時候都會同步編譯成js文件。教程如下：
在項目文件夾下運行命令：
tsc --init
項目文件夾下，會生成一個tsconfig.json文件。取消註釋 "outDir": "./js",，這就是輸出js文件所要存放的地址，這裏我改寫了在項目文件夾下的js文件夾。
{
"compilerOptions": {
/* Basic Options */
// "incremental": true, /* Enable incremental compilation */
"target": "es5", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
"module": "commonjs", /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
// "lib": [], /* Specify library files to be included in the compilation. */
// "allowJs": true, /* Allow javascript files to be compiled. */
// "checkJs": true, /* Report errors in .js files. */
// "jsx": "preserve", /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
// "declaration": true, /* Generates corresponding '.d.ts' file. */
// "declarationMap": true, /* Generates a sourcemap for each corresponding '.d.ts' file. */
// "sourceMap": true, /* Generates corresponding '.map' file. */
// "outFile": "./", /* Concatenate and emit output to single file. */
"outDir": "./js", /* Redirect output structure to the directory. */
// "rootDir": "./", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
// "composite": true, /* Enable project compilation */
// "tsBuildInfoFile": "./", /* Specify file to store incremental compilation information */
// "removeComments": true, /* Do not emit comments to output. */
// "noEmit": true, /* Do not emit outputs. */
// "importHelpers": true, /* Import emit helpers from 'tslib'. */
// "downlevelIteration": true, /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
// "isolatedModules": true, /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
/* Strict Type-Checking Options */
"strict": true, /* Enable all strict type-checking options. */
// "noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */
// "strictNullChecks": true, /* Enable strict null checks. */
// "strictFunctionTypes": true, /* Enable strict checking of function types. */
// "strictBindCallApply": true, /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
// "strictPropertyInitialization": true, /* Enable strict checking of property initialization in classes. */
// "noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */
// "alwaysStrict": true, /* Parse in strict mode and emit "use strict" for each source file. */
/* Additional Checks */
// "noUnusedLocals": true, /* Report errors on unused locals. */
// "noUnusedParameters": true, /* Report errors on unused parameters. */
// "noImplicitReturns": true, /* Report error when not all code paths in function return a value. */
// "noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */
/* Module Resolution Options */
// "moduleResolution": "node", /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
// "baseUrl": "./", /* Base directory to resolve non-absolute module names. */
// "paths": {}, /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
// "rootDirs": [], /* List of root folders whose combined content represents the structure of the project at runtime. */
// "typeRoots": [], /* List of folders to include type definitions from. */
// "types": [], /* Type declaration files to be included in compilation. */
// "allowSyntheticDefaultImports": true, /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
"esModuleInterop": true, /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
// "preserveSymlinks": true, /* Do not resolve the real path of symlinks. */
// "allowUmdGlobalAccess": true, /* Allow accessing UMD globals from modules. */
/* Source Map Options */
// "sourceRoot": "", /* Specify the location where debugger should locate TypeScript files instead of source locations. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Emit a single file with source maps instead of having a separate file. */
// "inlineSources": true, /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
/* Experimental Options */
// "experimentalDecorators": true, /* Enables experimental support for ES7 decorators. */
// "emitDecoratorMetadata": true, /* Enables experimental support for emitting type metadata for decorators. */
/* Advanced Options */
"forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
}
}
然後，在vs code編輯器上方的終端選項找到運行任務選項，點擊它。有兩個選項：
選擇 tsc:監視-tsconfig.json。就OK了。
4、安裝編輯器支持Typescript插件
這裏推薦Vs code的插件： TypeScript Hero
二、學習Typescript的數據類型
Typescript一共有10種數據類型。
- number類型
- string類型
- 數組類型
- 元組類型
- 枚舉類型
- boolean類型
- any類型
- null和undefined
- void 類型
- never 類型
// 1、number類型
let num:number=1;
console.log(num); // 1
// 2、string類型
let str:string='str';
console.log(str); // str
// 3、數組類型
let arr:number[]=[1,2,3];
console.log(arr); // [1,2,3]
let arr:string[]=['1','2','3'];
console.log(arr); // ['1','2','3']
let arr:Array<string>=['1','2','3'];
console.log(arr);
// 4、元組類型
let arrx:[number,string]=[1,'2'];
console.log(arrx); // [1,'2']
// 5、枚舉類型
enum flag {success=1,error=0};
let s:flag=flag.success;
console.log(s); //1
enum word {a,b,c};
let msg:word=word.b;
console.log(msg); //1
enum word {a,b=2,c};
let msg:word=word.c;
console.log(msg); //3