Regular expressions, commonly known as regex, are sequences of characters defining a search pattern used for string matching. They include literal characters matched exactly, meta-characters with special meanings (e.g., *, +, ^, $), character classes (defined in [] brackets), and quantifiers specifying the number of occurrences. Regex is a powerful tool for pattern-based string manipulation, widely employed in programming and text processing tasks. Mastery of regular expressions enhances a programmer's ability to efficiently search, validate, and manipulate text data within various applications and contexts.
Regex: Matching SSH Public Key
4 Feb, 2024
To match an SSH public key using regular expressions (regex), you can use the following pattern. SSH public keys typically start with "ssh-rsa" or another algorithm identifier, followed by the key...
Regex: Matching Roman Numerals
4 Feb, 2024
This regex is useful for validating and extracting Roman numerals in a given text or input. It's particularly handy in applications where you need to identify and work with Roman numerals, such as...
Regex: Matching HTML Self-Closing Tags
4 Feb, 2024
The following snippet employs a PCRE (Perl Compatible Regular Expressions) pattern to specifically identify and match self-closing HTML tags.
This pattern breaks down as follows:
< and >:...
Regex: select, if character is present
4 Feb, 2024
If you're looking to use regular expressions (regex) to check if a specific character is present in a string, you can use the following pattern in most programming languages: the ? quantifier makes...