- Everything you write in node is a module
- You can export a function is a module using “module.exports”
- You can use a exported module using “require”
- Example below
MathsDemo.js
function add(a, b){ return a+b; } function subtract(a,b){ return a-b; } module.exports.add = add;
ExecuteMaths.js
mathObject = require("./MathsDemo.js"); var output = mathObject.add(10,20); console.log('Result is : '+output);
Output :
Example : Writing data to a file
const fs = require('fs'); fs.writeFile('myfile', 'Hello World', (error)=>{ if(error) { console.log('Error while saving data'); } });
Example : Taking user input and storing data to file
const readline = require('readline'); //Read Line API const fs = require('fs'); //File System API const wirteToFile = (data) => { fs.writeFile('myfile', `${data}`, error => { if(error) { console.log('Data has been saved'); } }); }; const rl = readline.createInterface({ input: process.stdin, output: process.stdout }); rl.question('Enter data ', (data) => { wirteToFile(data); rl.close(); });