What is Perl style regular expression?
Regular Expression (Regex or Regexp or RE) in Perl is a special text string for describing a search pattern within a given text. Regex in Perl is linked to the host language and is not the same as in PHP, Python, etc. Sometimes it is termed as “Perl 5 Compatible Regular Expressions“.
What is the benefit of regular expressions?
Benefits of using Regular Expression Supported by almost any language, there are only a few programming languages which do not understand regular expressions; Do more with less, keep your code cleaner; Faster validations, instead of having many IF and ELSE operators you may validate only once with a regular expression.
What are the ways to implement regular expression in Perl?
There are three regular expression operators within Perl.
- Match Regular Expression – m//
- Substitute Regular Expression – s///
- Transliterate Regular Expression – tr///
What is Perl language used for?
Perl is a general-purpose programming language originally developed for text manipulation and now used for a wide range of tasks including system administration, web development, network programming, GUI development, and more.
What are metacharacters in Perl?
Basic Perl Metacharacters
| Metacharacter | Description |
|---|---|
| \r | matches a return character. |
| \s | matches any whitespace character, including space, tab, form feed, and so on, and is equivalent to [\f\n\r\t\v]. |
| \S | matches any character that is not a whitespace character and is equivalent to [^\f\n\r\t\v]. |
| \t | matches a tab character. |
What is a regular expression in PHP define the regular expression syntax and functions with suitable examples?
In PHP, regular expressions are strings composed of delimiters, a pattern and optional modifiers. $exp = “/w3schools/i”; In the example above, / is the delimiter, w3schools is the pattern that is being searched for, and i is a modifier that makes the search case-insensitive.
What does in regular expression mean?
Regular expressions (shortened as “regex”) are special strings representing a pattern to be matched in a search operation. For instance, in a regular expression the metacharacter ^ means “not”. So, while “a” means “match lowercase a”, “^a” means “do not match lowercase a”.