What are the regular expression wildcards?

Regular expression wildcards include ".", "*", " ", "?", "^", "$", "[]", "[^]", "[a-z]" , "[A-Z]", "[0-9]", "\d", "\D", "\w", "\W", "\s", "\S" and "\b". Detailed introduction: 1. ".", matches any single character, except newline characters; 2. ".", matches any single character, except newline characters; 3. " ", matches the previous character one or more times; 4. " ?"etc.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

Regular expression wildcards are special characters used to match text patterns. Commonly used regular expression wildcards include:

1, ".": matches any single character, except newline characters.

2. "*": Match the previous character zero or more times.

3. " ": Match the previous character one or more times.

4. "?": Match the previous character zero or one time.

5. "^": matches the beginning of the string.

6. "$": matches the end of the string.

7. "[]": Match any character within the brackets.

8. "[^]": Matches any character not within brackets.

9. "[a-z]": Match any lowercase letter.

10. "[A-Z]": Match any uppercase letter.

11. "[0-9]": Match any number.

12. "\d": matches any number, equivalent to "[0-9]".

13. "\D": matches any non-numeric character, equivalent to "[^0-9]".

14. "\w": matches any letter, number or underscore, equivalent to "[a-zA-Z0-9_]".

15. "\W": matches any non-letter, number or underscore, equivalent to "[^a-zA-Z0-9_]".

16. "\s": Matches any whitespace character, including spaces, tabs, newlines, etc.

17. "\S": Matches any non-blank character.

18. "\b": Match the boundary of the word.

These wildcard characters can be combined in regular expressions to match more complex text patterns. For specific usage of regular expression wildcards, please refer to the relevant regular expression tutorials and documentation.

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