| Nowa wersja | Poprzednia wersja |
| programowanie:regex:start [2024/08/25 22:12] – utworzono sases | programowanie:regex:start [2024/08/28 21:32] (aktualna) – sases |
|---|
| ====== Regex ====== | ====== Regex ====== |
| \\ | \\ |
| Platforma testująca: [[https://regexr.com/]] | Platforma testująca: [[https://regexr.com/]]\\ |
| | \\ |
| | |
| | === Metacharacters === |
| | Metacharacters are characters with a special meaning: |
| | |
| | ^ Character ^ Description ^ Example ^ |
| | | ''[]'' | A set of characters | ''[a-m]'' | |
| | | ''\'' | Signals a special sequence (can also be used to escape special characters) | ''\d'' | |
| | | ''.'' | Any character (except newline character) | ''he..o'' | |
| | | ''^'' | Starts with | ''^hello'' | |
| | | ''$'' | Ends with | ''planet$'' | |
| | | ''*'' | Zero or more occurrences | ''he.*o'' | |
| | | ''+'' | One or more occurrences | ''he.+o'' | |
| | | ''?'' | Zero or one occurrences | ''he.?o'' | |
| | | ''{}'' | Exactly the specified number of occurrences | ''he.{2}o'' | |
| | | ''|'' | Either or | ''falls|stays'' | |
| | | ''()'' | Capture and group || |
| | \\ |
| | |
| | === Brackets === |
| | Brackets are used to find a range of characters: |
| | |
| | ^ Bracket ^ Description ^ |
| | | ''[abc]'' | Find any character between the brackets | |
| | | ''[^abc]'' | Find any character NOT between the brackets | |
| | | ''[0-9]'' | Find any character between the brackets (any digit) | |
| | | ''[^0-9]'' | Find any character NOT between the brackets (any non-digit) | |
| | | ''(x|y)'' | Find any of the alternatives specified | |
| | \\ |
| | |
| | === Special Sequences === |
| | A special sequence is a ''\'' followed by one of the characters in the list below, and has a special meaning: |
| | |
| | ^ Character ^ Description ^ Example ^ |
| | | ''\A'' | Returns a match if the specified characters are at the beginning of the string | ''\AThe'' | |
| | | ''\b'' | Returns a match where the specified characters are at the beginning or at the end of a word \\ (the "r" in the beginning is making sure that the string is being treated as a "raw string") | ''\bain'' \\ ''ain\b'' | |
| | | ''\B'' | Returns a match where the specified characters are present, but NOT at the beginning (or at the end) of a word \\ (the "r" in the beginning is making sure that the string is being treated as a "raw string") | ''\Bain'' \\ ''ain\B'' | |
| | | ''\d'' | Returns a match where the string contains digits (numbers from 0-9) | ''\d'' | |
| | | ''\D'' | Returns a match where the string DOES NOT contain digits | ''\D'' | |
| | | ''\s'' | Returns a match where the string contains a white space character | ''\s'' | |
| | | ''\S'' | Returns a match where the string DOES NOT contain a white space character | ''\S'' | |
| | | ''\w'' | Returns a match where the string contains any word characters (characters from a to Z, digits from 0-9, and the underscore _ character) | ''\w'' | |
| | | ''\W'' | Returns a match where the string DOES NOT contain any word characters | ''\W'' | |
| | | ''\Z'' | Returns a match if the specified characters are at the end of the string | ''Spain\Z'' | |
| | \\ |
| | |
| | === Sets === |
| | A set is a set of characters inside a pair of square brackets ''[]'' with a special meaning: |
| | |
| | ^ Set ^ Description ^ |
| | | ''[arn]'' | Returns a match where one of the specified characters (''a'', ''r'', or ''n'') is present | |
| | | ''[a-n]'' | Returns a match for any lower case character, alphabetically between ''a'' and ''n'' | |
| | | ''[^arn]'' | Returns a match for any character EXCEPT ''a'', ''r'', and ''n'' | |
| | | ''[0123]'' | Returns a match where any of the specified digits (''0'', ''1'', ''2'', or ''3'') are present | |
| | | ''[0-9]'' | Returns a match for any digit between 0 and 9 | |
| | | ''[0-5][0-9]'' | Returns a match for any two-digit numbers from 00 and 59 | |
| | | ''[a-zA-Z]'' | Returns a match for any character alphabetically between a and z, lower case OR upper case | |
| | | ''[+]'' | In sets, ''+'', ''*'', ''.'', ''|'', ''()'', ''$'', ''{}'' has no special meaning, so ''[+]'' means: return a match for any ''+'' character in the string | |
| |