Regular Expressions 101

Pro

\d{3}a Unicode decimal digit, repeated exactly 3 times

Non-Capturing Group(?:[\-+](?:\d{4}(?:[\-+](?:\d{2})?)?)?)?

?repeats the group contents below at most once:

Character Class[\-+]

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Non-Capturing Group(?:\d{4}(?:[\-+](?:\d{2})?)?)?

?repeats the group contents below at most once:

\d{4}a Unicode decimal digit, repeated exactly 4 times

Non-Capturing Group(?:[\-+](?:\d{2})?)?

?repeats the group contents below at most once:

Character Class[\-+]

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Non-Capturing Group(?:\d{2})?

?repeats the group contents below at most once:

\d{2}a Unicode decimal digit, repeated exactly 2 times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

\d{3}(?:[\-+](?:\d{4}(?:[\-+](?:\d{2})?)?)?)?

New

Examples of strings that match:

    '123-1234-12'
    '123-1234-'
    '123-1234'
    '123-'
    '123'

Examples of strings that don't match:

    '1231234-12'
    '123-123412'
    '123--12'