Regular Expressions 101

Pro

1st Alternative\b((?:[A-Z]\.)+)\.?

\ba Unicode word boundary

Group 1((?:[A-Z]\.)+)

Non-Capturing Group(?:[A-Z]\.)+

+repeats the group contents below at least once:

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

2nd Alternative\.

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

\b((?:[A-Z]\.)+)\.?|\.

U.S.A is abbr  x.y  is not. But I.I.T. is also valid ABBVR and so is M.Tech

U.S.A is abbr  x.y  is not. But I.I.T. is also valid ABBVR and so is M.Tech