Question

I am really confused on this regex things. I have tried to understand it, went no where.

Basically, i am trying to replace all spaces followed by every character but a space to be replaced with “PM”.

” sd”
” sd”

however

” sd”
” sd”

Answer 1

This will replace the space and the following character with “PM”:

String s = "123 axy cq23 dasd"; //your string
String newString = s.replaceAll(" [^ ]","PM"); 

Since I’m not sure if you want to replace only the space or the space and the following character, too, here is a slightly modified version that replaces only the space:

String s = "123 axy cq23 dasd"; //your string
String newString = s.replaceAll(" ([^ ])", "PM$1")