Introduction to node js
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This document discusses using JavaScript at the backend with Node.js. It covers installing Node.js, creating a "Hello World" program, using Node's internal file system module, working with the Node Package Manager (NPM) to install external modules, and using an external module called lodash in a program.
![Using External Modules
var _ = require("lodash");
console.log(_.chunk(['a', 'b', 'c', 'd'], 2)); // [ [ 'a', 'b' ], [ 'c', 'd' ] ]
console.log(_.chunk(['a', 'b', 'c', 'd'], 3)); // [ [ 'a', 'b', 'c' ], [ 'd' ] ]
console.log(_.filter([4, 5, 6], function (n) {
return n % 2 == 0;
})); // [ 4, 6 ]](https://image.slidesharecdn.com/introductiontonodejs-170303044245/85/Introduction-to-node-js-26-320.jpg)
Introduction to node js
- 2. Agenda
- 6. Agenda 1. What? 2.Installing 3.Hello World. 4.NodeJS Internal Modules
- 7. Agenda 1. What? 2.Installing 3.Hello World. 4.NodeJS Internal Modules ○fs(file-system) (sync vs async)
- 8. Agenda 1. What? 2.Installing 3.Hello World. 4.NodeJS Internal Modules ○fs(file-system) (sync vs async) 5. NPM
- 9. Agenda 1. What? 2.Installing 3.Hello World. 4.NodeJS Internal Modules ○fs(file-system) (sync vs async) 5. NPM 6. Using External Modules
- 10. What?
- 12. Hello World
- 13. You can checkout Demo form: https://github.com/AmitThakkar/JavaScript-at-Backend-NodeJS
- 14. Node Internal Modules: fs var fs = require('fs'); fs.unlinkSync('test2'); console.log('successfully deleted test2');
- 15. Node Internal Modules: fs var fs = require('fs'); fs.unlinkSync('test2'); console.log('successfully deleted test2');
- 16. Node Internal Modules: fs var fs = require('fs'); fs.unlinkSync('test2'); console.log('successfully deleted test2');
- 17. Node Internal Modules: fs var fs = require('fs'); fs.unlink('test', function (err) { if (err) throw err; console.log('successfully deleted test'); });
- 18. Node Internal Modules: fs var fs = require('fs'); fs.unlink('test', function (err) { if (err) throw err; console.log('successfully deleted test'); });
- 19. Node Internal Modules: fs var fs = require('fs'); fs.unlink('test', function (err) { if (err) throw err; console.log('successfully deleted test'); });
- 20. You can checkout Demo form: https://github.com/AmitThakkar/JavaScript-at- Backend-NodeJS
- 21. NPM 1. Node Package Manager 2. The NPM command-line tool is bundled with node. 3. npm init 4. npm install --save lodash 5. npm uninstall --save lodash
- 22. npm init
- 23. npm install --save lodash
- 24. npm uninstall --save lodash
- 25. You can checkout Demo form: https://github.com/AmitThakkar/JavaScript-at- Backend-NodeJS
- 26. Using External Modules var _ = require("lodash"); console.log(_.chunk(['a', 'b', 'c', 'd'], 2)); // [ [ 'a', 'b' ], [ 'c', 'd' ] ] console.log(_.chunk(['a', 'b', 'c', 'd'], 3)); // [ [ 'a', 'b', 'c' ], [ 'd' ] ] console.log(_.filter([4, 5, 6], function (n) { return n % 2 == 0; })); // [ 4, 6 ]
- 27. You can checkout Demo form: https://github.com/AmitThakkar/JavaScript-at- Backend-NodeJS
- 28. Questions??
- 29. References: Create Basic HTTP Server with Node.js