Regular Expressions 101

Pro

^start of line

Group 1(202[01])

202the literal text 202

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-9]{4}

{4}matches exactly 4 characters from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

abcthe literal text abc (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 2(dat|csv)

1st Alternativedat

datthe literal text dat (case sensitive)

2nd Alternativecsv

csvthe literal text csv (case sensitive)

$end of line

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

^(202[01])[0-9]{4}abc\.(dat|csv)$

01990205abc.dat
20200304abc.dat
20210506abc.csv

01990205abc.dat
20200304abc.dat
20210506abc.csv