Regular Expressions 101

Explanation

Pro

^start of line

\s*any whitespace character, repeated any number of times

Group 1((([+]?(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s+){2}([+]?((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s*)|((\-1(\.(0)*)?([Ee][+-]?[0]+)?\s+){2}\-1(\.(0)*)?([Ee][+-]?[0]+)?)\s*)?

?repeats the group contents below at most once:

1st Alternative(([+]?(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s+){2}([+]?((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s*)

Group 2(([+]?(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s+){2}([+]?((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s*)

Group 3([+]?(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s+){2}

{2}repeats the group contents below exactly 2 times:

Character Class[+]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Group 4(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)

Group 5((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)

1st Alternative(0|[1-9][0-9]*)(\.[0-9]*)?

Group 6(0|[1-9][0-9]*)

1st Alternative0

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

2nd Alternative[1-9][0-9]*

Character Class[1-9]

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

Character Class[0-9]*

*matches any number of characters from the set below:

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

Group 7(\.[0-9]*)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[0-9]*

*matches any number of characters from the set below:

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

2nd Alternative\.[0-9]+

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[0-9]+

+matches at least one character from the set below:

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

Group 8([Ee][+-]?[0-9]+)?

?repeats the group contents below at most once:

Character Class[Ee]

Ethe literal E (69₁₀ / 105₈ / 45₁₆) (case sensitive)

ethe literal e (101₁₀ / 145₈ / 65₁₆) (case sensitive)

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[0-9]+

+matches at least one character from the set below:

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

\s+any whitespace character, repeated at least once

Group 9([+]?((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)

Character Class[+]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Group 10((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)

1st Alternative(0|[1-9][0-9]*)(\.[0-9]*)?

Group 11(0|[1-9][0-9]*)

Group 12(\.[0-9]*)?

2nd Alternative\.[0-9]+

Group 13([Ee][+-]?[0-9]+)?

\s*any whitespace character, repeated any number of times

2nd Alternative((\-1(\.(0)*)?([Ee][+-]?[0]+)?\s+){2}\-1(\.(0)*)?([Ee][+-]?[0]+)?)\s*

$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

Unit Test Summary

Ready to run

Quick Reference

26 tokens

Regular Expression

^\s*((([+]?(((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s+){2}([+]?((0|[1-9][0-9]*)(\.[0-9]*)?|\.[0-9]+)([Ee][+-]?[0-9]+)?)\s*)|((\-1(\.(0)*)?([Ee][+-]?[0]+)?\s+){2}\-1(\.(0)*)?([Ee][+-]?[0]+)?)\s*)?$

Regular Expression

Unit Tests