Regular Expressions 101

^start of line

Group 1((?:[+-]?\d+(?:[.]\d+)?)(?:[ \t]|$))*

*repeats the group contents below any number of times:

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

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a Unicode decimal digit, repeated at least once

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

?repeats the group contents below at most once:

Character Class[.]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a Unicode decimal digit, repeated at least once

Non-Capturing Group(?:[ \t]|$)

1st Alternative[ \t]

Character Class[ \t]

the literal (32₁₀ / 40₈ / 20₁₆)

\ta tab character (ASCII 9)

2nd Alternative$

$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+)?)(?:[ \t]|$))*$

New

Should match:
15 35 -45 8 -2.3 4564.18 56
22
1 2 3
+45

Not match
two spaces between
1  23
two decimals:
1..23
spaces at the end:
123