define variable javascript code example

Example 1: javascript declare a variable

//choose the best for your solution
var myVariable = 22; //this can be a string or number. var is globally defined

let myVariable = 22; //this can be a string or number. let is block scoped

const myVariable = 22; //this can be a string or number. const is block scoped and can't be reassigned

Example 2: js variables

//Making variables with let:
let numberOfFriends = 1;

//Incrementing:
numberOfFriends += 3; //numberOfFriends is now 4

// Variables with const
const minimumAge = 21; //CANNOT REASSIGN!

//Booleans - true or false values
true;
false;
let isHappy = true;

//Naming Conventions
// Use upper camel-cased names:
let numberOfChickens = 6; //GOOD
// NOT THE JS WAY:
// let number_of_chickens = 6;

Example 3: variable javascript

//You can make a variable by using:
var variable-name = 'defenition of the variable';
// Or you can use
let variable-name = 'defenition of the variable';

Example 4: 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 5: js variables

// let & var are both editable variables:
var cow = 'moo';
let pig = 'oink';
cow = 10;
pig = 10;
// const is a permanent variable; you cannot change it.
const uncuttableGrass = '\/\/';
uncuttableGrass = '___';
// above throws an error

Example 6: Create variable javascript

//Assigns the value bar to the variable foo
var foo = bar;