Simpatico Kata: Regular Expressions

See: home, reflector

Regular expressions are hard. Regular expressions in JavaScript are even harder. Regular expressions in JavaScript in the browser are the hardest. See regex 101 for a good regex tester.

Common use cases

// Does a string contain a substring?
assertEquals(true, /foo/.test('foobar'));
assertEquals(false, 'foobar'.indexOf('foo') === -1);

// Regex literals in javascript: the following are equivalent:
const regex = /foo/gm;
const regex = new RegExp('foo', 'gm');