Reverse Number

Reverse Number.markdown

Reverse Number

Example of how to reverse number using JavaScript

A Pen by Vlad Bezden on CodePen.

License.

script.js

'use strict';

describe('reverse', () => {
	const msg = 'should reverse 123 to 321',
		actual = reverse(123),
		expected = 321;

	it(msg, () => {
		expect(expected).toEqual(actual);
	});
});

function reverse(n) {
	let result = 0;

	while (n > 0) {
		result = result * 10 + n % 10;
		n = Math.floor(n / 10);
	}
	return result;
}

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine-html.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/boot.min.js"></script>

styles

<link href="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine.min.css" rel="stylesheet" />