Regular Expressions 101

Pro

^start of line

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

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

\d*?a digit, repeated any number of times

Group 1([1-9].*?|0[1-9].*?|0$)

1st Alternative[1-9].*?

Character Class[1-9]

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

.*?any character (except for line terminators), repeated any number of times

2nd Alternative0[1-9].*?

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

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

.*?any character (except for line terminators), repeated any number of times

3rd Alternative0$

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

$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

Regular Expression

^-?\d+\.?\d*?([1-9].*?|0[1-9].*?|0$)

2.001469, should be trimmed to 2.001
15 should stay as it is, since it has no decimals
-7.00000046598 should be trimmed to -7.0000004
15.135 should be trimmed to 15.1
0.00004123456
.1538