Learn typescript with VAM (phase 1)

One 、 Installation environment and configuration 1、 Command line install

npm i -g typescript

2、 Quick open Vs Code Editor

Create a project folder , Open the command line tool in this folder , Use code . Command to quickly open the editor （ If the computer prompts that there is no such command , Please find the editor installation directory bin Under the folder , Copy address . To systematic environment variable Next Path, edit , Add in front ;, Just paste it in ）. 3、 function typesript And synchronization typesript And js transformation

In the project folder, we create a file named demo1.ts file . This is what we learn typesript The starting point of the , Remember typesript Need to be converted to js The file can be recognized by the browser , So you need to run the command ：

tsc demo1.ts

This will generate a folder named demo1.js file . Is it annoying to run commands every time you finish writing , So we recommend using Vs code Editor , Every time you write ts Will be synchronously compiled into js file . The tutorial is as follows ： Run the command under the project folder ：

tsc --init

Project folder , Will generate a tsconfig.json file . uncomment “outDir”: “./js”,, This is the output js The address where the document is to be stored , Here I rewrote the project folder js Folder .

{ “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. */

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For more information, please refer to the original , Reproduced from ：https://blog.csdn.net/weixin_44519496/article/details/119945555