Bootstrap

1. Install bootstrap

             npm install bootstrap

bootstrap folders will be installed in node_modules folder

bootstrap package version will be added to the file package.json

2. add the css and js file to angular.json

1. open angular.json

2. add css file to the parameter 'styles'

3. add js files to the parameter 'scripts'

{ 
     "$schema": "./node_modules/@angular/cli/lib/config/schema.json", 
      "version": 1, 
        "newProjectRoot": "projects", 
         "projects": {    "angular-bootstrap-examples": {      "projectType": "application",      "schematics": {},      "root": "",      "sourceRoot": "src",      "prefix": "app",      "architect": {        "build": {          "builder": "@angular-devkit/build-angular:browser",          "options": {            "outputPath": "dist/angular-bootstrap-examples",            "index": "src/index.html",            "main": "src/main.ts",            "polyfills": "src/polyfills.ts",            "tsConfig": "tsconfig.app.json",            "aot": true,        
              "assets": [              "src/favicon.ico",              "src/assets"            ],     
                     "styles": [              "./node_modules/bootstrap/dist/css/bootstrap.css",              "src/styles.css"                          ],     
                            "scripts": [              "./node_modules/jquery/dist/jquery.js",              "./node_modules/bootstrap/dist/js/bootstrap.js"            ]          },

2. Other libraries

Toster

npm install ngx-toastr --save
         

add in angular.json

         "styles": [  
           "./node_modules/bootstrap/dist/css/bootstrap.css",    
                   "src/styles.css"   
                   "./node_modules/ngx-toastr/toastr.css",
                   ],