initial commit

Author: bobbyhadz

.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+.pnpm-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional stylelint cache
+.stylelintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+.parcel-cache
+
+# Next.js build output
+.next
+out
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# vuepress v2.x temp and cache directory
+.temp
+.cache
+
+# Docusaurus cache and generated files
+.docusaurus
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# yarn v2
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.yarn/install-state.gz
+.pnp.*

README.md

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+## Instructions
+
+The JS code is in the `index.js` file.
+
+To be able to run the code, follow these instructions:
+
+1. Clone the GitHub repository with the `git clone` command.
+2. Open your terminal in the project's root directory (right next
+   to `package.json`).
+3. Install the node modules.
+
+```bash:shell
+npm install
+```
+
+4. To run the code, issue the `npm start` command.
+
+```bash:shell
+npm start
+```
+
+Alternatively, you can run the project in watch mode, so every
+time you save, the JavaScript server is restarted.
+
+```bash:shell
+npm run dev
+```
+
+The `npm run dev` command uses `nodemon` to watch for changes and
+restarts your JavaScript project every time you save (Ctrl + S).

index.js

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+// EXAMPLE 1 - Convert an Array of Objects to an Array of Values in JS
+
+const arrOfObj = [
+  {id: 1, name: 'Alice'},
+  {id: 2, name: 'Bob'},
+];
+
+const arr = arrOfObj.map(object => object.name);
+console.log(arr); // 👉️ ['Alice', 'Bob']
+
+// ------------------------------------------------------------------
+
+// // EXAMPLE 2 - Dealing with missing properties
+
+// const arr = [
+//   {id: 1, name: 'Alice'},
+//   {id: 2},
+//   {id: 3, name: 'Carl'},
+// ];
+
+// const names = arr.map(obj => obj.name);
+// console.log(names); // 👉️ ['Alice', undefined, 'Carl']
+
+// ------------------------------------------------------------------
+
+// // EXAMPLE 3 - Removing the undefined values from the array
+
+// const arr = [
+//   {id: 1, name: 'Alice'},
+//   {id: 2},
+//   {id: 3, name: 'Carl'},
+// ];
+
+// const names = arr
+//   .map(obj => obj.name)
+//   .filter(value => {
+//     return value !== undefined;
+//   });
+// console.log(names); // 👉️ ['Alice', 'Carl']
+
+// ------------------------------------------------------------------
+
+// // EXAMPLE 4 - Convert an Array of Objects to an Array of Values using `forEach()`
+
+// const arrOfObj = [
+//   {id: 1, name: 'Alice'},
+//   {id: 2, name: 'Bob'},
+// ];
+
+// const arr = [];
+
+// arrOfObj.forEach(object => {
+//   arr.push(object.name);
+// });
+
+// console.log(arr); // 👉️ ['Alice', 'Bob']
+
+// ------------------------------------------------------------------
+
+// // EXAMPLE 5 - Convert an Array of Objects to an Array of Values using `for...of`
+
+// const arrOfObj = [
+//   {id: 1, name: 'Alice'},
+//   {id: 2, name: 'Bob'},
+// ];
+
+// const arr = [];
+
+// for (const object of arrOfObj) {
+//   arr.push(object.name);
+// }
+
+// console.log(arr); // 👉️ ['Alice', 'Bob']
+
+// ------------------------------------------------------------------
+
+// // EXAMPLE 6 - Convert an Array of Objects to an Array of Values using `for`
+
+// const arrayOfObjects = [
+//   {id: 1, name: 'Alice'},
+//   {id: 2, name: 'Bob'},
+// ];
+
+// const arr = [];
+
+// for (let index = 0; index < arrayOfObjects.length; index++) {
+//   arr.push(arrayOfObjects[index].name);
+// }
+
+// console.log(arr); // 👉️ ['Alice', 'Bob']