Regular Expressions 101

^start of line

Non-Capturing Group(?:(?<real>\d+(?:(?:\.\d+)?(?:e[+\-]\d+)?)?)?(?:[+\-]))?

?repeats the group contents below at most once:

Group real(?<real>\d+(?:(?:\.\d+)?(?:e[+\-]\d+)?)?)?

?repeats the group contents below at most once:

\d+a digit, repeated at least once

Non-Capturing Group(?:(?:\.\d+)?(?:e[+\-]\d+)?)?

?repeats the group contents below at most once:

Non-Capturing Group(?:\.\d+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Non-Capturing Group(?:e[+\-]\d+)?

?repeats the group contents below at most once:

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

Character Class[+\-]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Non-Capturing Group(?:[+\-])

Character Class[+\-]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group imaginary(?<imaginary>\d+(?:(?:\.\d+)?(?:e[+\-]\d+)?)?)?

?repeats the group contents below at most once:

\d+a digit, repeated at least once

Non-Capturing Group(?:(?:\.\d+)?(?:e[+\-]\d+)?)?

?repeats the group contents below at most once:

Non-Capturing Group(?:\.\d+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Non-Capturing Group(?:e[+\-]\d+)?

?repeats the group contents below at most once:

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

Character Class[+\-]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Character Class[iI]

ithe literal i (105₁₀ / 151₈ / 69₁₆) (case sensitive)

Ithe literal I (73₁₀ / 111₈ / 49₁₆) (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.

Search reference

Regular Expression

^(?:(?<real>\d+(?:(?:\.\d+)?(?:e[+\-]\d+)?)?)?(?:[+\-]))?(?<imaginary>\d+(?:(?:\.\d+)?(?:e[+\-]\d+)?)?)?[iI]$

New

1.23e+45-67.89e-1256i
3
3+4i
3+4I
3-4i
+4i
-2i
3+i
4-i
+i
-i
i