Setup Project
- mkdir /Fundamentals
- cd Fundamentals
- npm init
- defaults
- npm install –save-dev babel-cli
- npm install –save-dev babel-preset-es2015 babel-preset-stage-2
- touch variables.js
- atom .
package.json
{
“name”: “Fundamentals”,
“version”: “1.0.0”,
“description”: “”,
“main”: “variables.js”,
“scripts”: {
“test”: “echo \”Error: no test specified\” && exit 1″,
“start”: “nodemon variables.js –exec babel-node –presets es2015,stage-2”
},
“author”: “”,
“license”: “ISC”,
“devDependencies”: {
}
}
[/code]
variables.js
"use strict"; var firstname = "Jon"; var lastname = "Doe"; var age = 21; var married = false; var sex = 'M' console.log(firstname); console.log(age); console.log(married); console.log(sex); console.log(firstname+" "+lastname); // ES5 console.log(firstname,lastname); // ES5 console.log(`${firstname} ${lastname}`); // ES6 console.log(`Fullname: ${firstname} ${lastname} - (${sex}) ${age} - Married: ${married}`); // ES6 var fullname = `${firstname} ${lastname}` // ES6 console.log(fullname); // let var people = ['Jon Doe', 'Jane Doe', 'Mick Doe']; // Pollutes global namespace. for (var i = 1; i <= people.length; i += 1) { console.log(`person ${i} is ${people[i-1]}.`); } console.log(i); // 4 // Only in scope in the for for (let j = 1; j <= people.length; j += 1) { console.log(`person ${j} is ${people[j-1]}.`); } try { console.log(j); // Reference error } catch (err) { console.log(`Error: ${err}.`); } // const const PI = 3.142 console.log(PI); // PI = 6; // Syntax error - PI is readonly
Better to use let and const instead of var
Start Node and run the code
- npm start