When should you prefer backreferences, and when should you avoid it?

Backreferences in Perl are a powerful feature that allows you to refer back to previously captured groups in regular expressions. However, they should be used judiciously. Here are some guidelines:

When to Prefer Backreferences:

• Pattern Repetition: Use backreferences when you need to match repeated patterns within a string. For example, matching pairs of parentheses or quotes.
• Complex String Validation: Ideal for validating strings that must contain repeated sections, like duplicate words or mirrored sequences.

When to Avoid Backreferences:

• Performance Concerns: Backreferences can significantly slow down regex performance, especially with complex patterns and large datasets. Consider alternatives if performance is a concern.
• Code Readability: Using too many backreferences can make regex harder to read and maintain. Simpler patterns are often easier to understand.

Example of Backreference in Perl