awesome-REGEX

Awesome regular expression (REGEX) commands anyone must know:

1. Exact Match: The most basic form of regex involves matching a sequence of characters. For instance, if you want to match 'Hello World', you can simply use Hello World as your regex.

2. Any Character (.): The dot . matches any character except a newline character. For example, a.b can match 'acb', 'a2b', 'a$b', etc.

3. Zero or More (*): The asterisk * matches zero or more instances of the preceding character. For example, a* can match '', 'a', 'aa', 'aaa', etc.

4. One or More (+): The plus + matches one or more occurrences of the preceding character. For example, a+ can match 'a', 'aa', 'aaa', etc., but not an empty string.

5. Zero or One (?): The question mark ? matches zero or one occurrence of the preceding character. For example, a? can match '' or 'a'.

6. Character Set ([]): Square brackets [] define a character class, matching any character within the brackets. For example, [abc] can match 'a', 'b', or 'c'.

7. Ranges (-): You can specify a range of characters using - inside a character set. For example, [a-z] matches any lowercase letter, and [0-9] matches any digit.

8. Negation (^): The caret ^ at the start of a character set negates the set, matching any character not in the set. For example, [^0-9] matches any non-digit character.

9. Groups and Capturing (() and $1, $2, etc.): Parentheses () are used to create a group, which can be referenced in the replace pattern. For example, (abc) creates a group matching the string 'abc', and $1 in the replace pattern refers to this group.

10. Alternation (|): The pipe | acts like a boolean OR, matching the pattern before or the pattern after it. For example, abc|def matches 'abc' or 'def'.