正则表达式，用于选择带有数字值的大括号并忽略大括号内的空格

Question

I have a string which looks something like this

(100) + (1000    )

I have to select both numbers along with braces ignoring the whitespace within them.

I was able to select (100) using the expression

\(-?[0-9]\d*(\.\d+)?\)

But I could not find any way to select (1000 ) where I can ignore spaces.

Can anyone help me out with this?

Answer 1

Just add optional spaces on both side:

\(\s*-?[0-9]\d*(\.\d+)?\s*\)
  ^^^                  ^^^

Answer 2

The following pattern should match in both cases:

\(-?\d+(\.\d+)?\s*\)

If you want to also allow for spaces at the beginning, you could use this:

\(\s*-?\d+(\.\d+)?\s*\)

Note: \\d+ means the same thing as [0-9]\\d* . If what you really meant was [1-9]\\d* (to disallow leading zeros), then you'd want to use that in place of the \\d+ .