RegEx that will match the last occurrence of dot in a string

Question

I have a filename that can have multiple dots in it and could end with any extension:

tro.lo.lo.lo.lo.lo.png

I need to use a regex to repla

Answer 1

To match all characters from the beginning of the string until (and including) the last occurence of a character use:

^.*\.(?=[^.]*$)  To match the last occurrence of the "." character

^.*_(?=[^.]*$)   To match the last occurrence of the "_" character