True or False: Perl regular expressions must start and end with a delimiter.

Perl regular expressions indeed require that expressions start and end with a delimiter. This is a fundamental aspect of how Perl handles regular expressions. The delimiters mark the beginning and the end of the pattern that is to be matched against the target string. The most commonly used delimiter is the forward slash (/) but Perl allows for other characters to serve as delimiters as long as they are consistent at both ends of the expression.

For example, in the pattern /pattern/, the slashes are the delimiters. This syntax is essential, as it helps differentiate the regular expression from any other code or text in the program.

Other options suggest conditions or contexts under which the usage of delimiters might change, but in reality, regardless of the context, a Perl regular expression will consistently require delimiters for it to be recognized properly in the code. This is why stating that regular expressions must start and end with a delimiter is clearly true.