regex101: JavaScript Match Workspace

^start of line

Positive Lookahead(?=[iI.\d+-])

Character Class[iI.\d+-]

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

Ithe literal I (73₁₀ / 111₈ / 49₁₆) (case sensitive)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 1([+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?(?![iI.\d]))?

?repeats the group contents below at most once:

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

1st Alternative\d+(?:\.\d*)?

\d+a digit, repeated at least once

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

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d*a digit, repeated any number of times

2nd Alternative\.\d+

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

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

?repeats the group contents below at most once:

Character Class[eE]

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

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

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Negative Lookahead(?![iI.\d])

Character Class[iI.\d]

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

Ithe literal I (73₁₀ / 111₈ / 49₁₆) (case sensitive)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

Group 2([+-]?(?:(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?)?[iI])?

?repeats the group contents below at most once:

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?)?

?repeats the group contents below at most once:

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

1st Alternative\d+(?:\.\d*)?

\d+a digit, repeated at least once

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

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d*a digit, repeated any number of times

2nd Alternative\.\d+

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

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

?repeats the group contents below at most once:

Character Class[eE]

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

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

Character Class[+-]?

?matches at most one character from the set below:

+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

Search reference

Regular Expression

^(?=[iI.\d+-])([+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?(?![iI.\d]))?([+-]?(?:(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?)?[iI])?$

New

1.1

1.1+2.2i

1.1-2.2i

+2.2i

-2.2i

1.1+i

1.1-i

i

-i

Regular Expressions 101

Regular Expression

Extraction