Basic character classes

⬅️ Execute Program RegEx

Basic character classes

• \d for digits
• \s for whitespace (spaces, newlines, tabs, etc.)
• Making these character classes upper-case negates them. For example, \d is all digits. But \D is any character that isn’t a digit.

/^\d*$/.test('3000')
var re = /^\d\d\d-\d\d\d\d$/;