Question

I have multiple types of strings. If it is like number text (text) I want to erase the content inside the brackets. Otherwise not.

This will remove everything always inside brackets.

/\((.*?)\)/

How do I check for the leading number?

Answer 1

Use this regex

(\d[^\(\)]*?\().*?(\))
    ^           ^   ^
    |           |   |->2nd group matches )
    |           |->matches content within ()
    |->1st group would match a digit followed by 0 to many characters(except ())followed by (

and replace it with

$1$2