JavaScript variables are containers for storing data values. In this example, x, y, and z, are variables, declared with the var keyword: Example var x = 5; var y = 6; var z = x + y;

Example 1: how to declare a variable js

//let and var are both editable variables and can be changed later on in your program;
let dog = 'Woof';
//dog is equal to the string 'Woof';
dog = false;
//You can changed the value of dog now because it was defined with let and not const;

let cow = 'Moo';
//cow is equal to the string 'Moo';
cow = true;
//You can change the value of cow later on because it is not defined with const;

//const is used when declaring a variable that can't be changed later on -- const stands for constant;
const pig = 'oink';
//This assigns the string 'oink' to pig which can not be changed because it is defined with const;
pig = 'snort';
//Above throws an error
//Good Job you now know how to declare variables using JavaScript!!!

Example 2: how to declare variables javascript

//variables are a way to easily store data in javascript
//variables are declared by the var keyword, example...
var x = 10;
//or
var dog_name = "daisy";
//which can also be written as 
var dog_name = 'daisy';
//same thing with single quotes and double quotes