Line numbers make your code far less flexible.

If your want to insert a piece of code, you will have to renumber all your lines. Sure, you might number with increments of 10, but then, what if you want to insert 11 lines of code? Or first you insert 10 lines, then later on, between that, another 10?

Also, what are you going to do with statements that are longer than a line? Can you just arbitrary put numbers in those statements? It gets worse with strings that span multiple lines. Do they need to be numbered?

The bottom line is, there is absolutely no reason to number the lines of your code. If you find it handy to have line numbers while coding, use power editor like vi that will allow you to view line numbers.

Note that you can use line numbers in Perl. Or at least, sort of:

L0: print "Begin of program.\n";
L1: print "Hello, world.\n";
L2: ;# Some comment.
L3: print "End of program.\n";
[download]

Begin of program.
Hello, world.
End of program.

Abigail