Regular Expressions 101

Pro

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

1st Alternative(^[1-9])(\d{0,4})

Group 2(^[1-9])

^start of line

Character Class[1-9]

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

Group 3(\d{0,4})

\d{0,4}a digit, repeated between 0 and 4 times

2nd Alternative^0

^start of line

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

3rd Alternative^

^start of line

Group 4((\.?)\d{0,4})

Group 5(\.?)

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

\d{0,4}a digit, repeated between 0 and 4 times

Group 6(|[A-Za-z])

1st Alternative — matches an empty string

2nd Alternative[A-Za-z]

Character Class[A-Za-z]

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

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

$end of line

the literal ↵ (10₁₀ / 12₈ / A₁₆)

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

((^[1-9])(\d{0,4})|^0|^)((\.?)\d{0,4})(|[A-Za-z])$

New

.309x
0.309
1
0.0
1.0234
0.2345X
1.23A
7300.3211x
0.1a

01.123
00.234
a.123
1.23p
00.43x

.309x
0.309
1
0.0
1.0234
0.2345X
1.23A
7300.3211x
0.1a

01.123
00.234
a.123
1.23p
00.43x