Regular Expressions 101

^start of line

Group 1([1-9]\d{0,3}|1\d{4}|2[0-4]\d{3}|25000)

1st Alternative[1-9]\d{0,3}

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\d{0,3}a digit, repeated between 0 and 3 times

2nd Alternative1\d{4}

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

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

3rd Alternative2[0-4]\d{3}

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

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

4th Alternative25000

25000the literal text 25000

$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.

26 tokens

Regular Expression

^([1-9]\d{0,3}|1\d{4}|2[0-4]\d{3}|25000)$

New

Matches
-------
1
9
10
100
999
1000
9999
10000
20000
24999
25000

Doesn't match
-------------
0
01
00009
25001
99999