how to declare variables 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';var <variable-name>;

var <variable-name> = <value>;
// 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//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