It doesn't make a difference, but if you want to write something after the variable, it's treated literally unless there's an \E. That's a common mistake I made, so I always haven an \E for every \Q.

Example: 

$ perl -Mre=debug -e 'my $x= "*"; /\Q$x.+/'
Compiling REx "\*\.\+"
Final program:
   1: EXACT <*.+> (3)
   3: END (0)
anchored "*.+" at 0 (checking anchored isall) minlen 3 
Freeing REx: "\*\.\+"

[download]
You see that the .+ is also treated literally.

In reply to Re^4: Regex help by moritz
in thread Regex help by bingohighway

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