scopes.js

/*
 * Below is an example of when to use `var` and `let`
 */

'use strict';

let a = 'a';
var b = 'b';
const c = 'c';

{
	let d = 'd';
}

{
	var e = 'e';
}

console.log( a );
console.log( b );
console.log( c );
//console.log( d ); => throws error
console.log( e );