Regular Expressions 101

^start of line

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

Group 1([.]\d+)?

?repeats the group contents below at most once:

Character Class[.]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Group 2([+\-*/][+-]?\d+([.]\d+)?)*

*repeats the group contents below any number of times:

Character Class[+\-*/]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

*the literal * (42₁₀ / 52₈ / 2A₁₆)

/the literal / (47₁₀ / 57₈ / 2F₁₆)

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

Group 3([.]\d+)?

?repeats the group contents below at most once:

Character Class[.]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

$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

^[+-]?\d+([.]\d+)?([+\-*/][+-]?\d+([.]\d+)?)*$

5+4
3+6*6-9/8
3.0+6.0
-1+-1
44-5
-7
+6
/8
*8
8.0
5.2.2
3.2+4
3.2+3.2
2+5.4
5--5
+5*4*3)
6*(4)
5*(5+6)