How to replace whitespace with notepad++ between two characters

Question

I have question how to replace whitespace with _ using notepad++ regex between [] characters

Example :

sl.[Posting date]                       AS TIME, 
         


        

Answer 1

Use

Regex Replace

(\[[^ ]*) +(.*\])

with

$1_$2

if you want to replace multiple space character with a single _ OR

Regex Replace

(\[[^ ]*) (.*\])

with

$1_$2

if you want to replace each space character with a single _