```
| Regex String | Functionality                                             | Use Case and Location                     | Breakdown and Explanation                                                                |
|--------------|-----------------------------------------------------------|-------------------------------------------|------------------------------------------------------------------------------------------|
| \d           | Matches any digit                                         | Form input validation                     | \d is a shorthand for [0-9], and matches any digit character                             |
| \w           | Matches any alphanumeric character                        | Password validation                       | \w is a shorthand for [a-zA-Z0-9_], and matches any alphanumeric character or underscore |
| \s           | Matches any whitespace character                          | Text processing                           | \s matches any whitespace character such as space, tab, or newline                       |
| ^            | Matches the beginning of a line                           | Text processing                           | ^ is an anchor that matches the beginning of a line                                      |
| $            | Matches the end of a line                                 | Text processing                           | $ is an anchor that matches the end of a line                                            |
| .            | Matches any character except newline                      | Text processing                           | . matches any character except newline                                                   |
| +            | Matches one or more occurrences of the preceding pattern  | Form input validation                     | + matches one or more occurrences of the preceding pattern                               |
| *            | Matches zero or more occurrences of the preceding pattern | Text processing                           | * matches zero or more occurrences of the preceding pattern                              |
| ?            | Matches zero or one occurrence of the preceding pattern   | URL routing                               | ? matches zero or one occurrence of the preceding pattern                                |
| [abc]        | Matches any character in the set (a, b, or c)             | Form input validation                     | [abc] matches any character that is either a, b, or c                                    |
| [a-z]        | Matches any character in the range a to z                 | Text processing                           | [a-z] matches any lowercase letter from a to z                                           |
| (abc \| def) |  Matches either the pattern "abc" or "def" | Text processing
```
| Regex String | Functionality                                             | Use Case and Location                     | Breakdown and Explanation                                                                |
|--------------|-----------------------------------------------------------|-------------------------------------------|------------------------------------------------------------------------------------------|
| \d           | Matches any digit                                         | Form input validation                     | \d is a shorthand for [0-9], and matches any digit character                             |
| \w           | Matches any alphanumeric character                        | Password validation                       | \w is a shorthand for [a-zA-Z0-9_], and matches any alphanumeric character or underscore |
| \s           | Matches any whitespace character                          | Text processing                           | \s matches any whitespace character such as space, tab, or newline                       |
| ^            | Matches the beginning of a line                           | Text processing                           | ^ is an anchor that matches the beginning of a line                                      |
| $            | Matches the end of a line                                 | Text processing                           | $ is an anchor that matches the end of a line                                            |
| .            | Matches any character except newline                      | Text processing                           | . matches any character except newline                                                   |
| +            | Matches one or more occurrences of the preceding pattern  | Form input validation                     | + matches one or more occurrences of the preceding pattern                               |
| *            | Matches zero or more occurrences of the preceding pattern | Text processing                           | * matches zero or more occurrences of the preceding pattern                              |
| ?            | Matches zero or one occurrence of the preceding pattern   | URL routing                               | ? matches zero or one occurrence of the preceding pattern                                |
| [abc]        | Matches any character in the set (a, b, or c)             | Form input validation                     | [abc] matches any character that is either a, b, or c                                    |
| [a-z]        | Matches any character in the range a to z                 | Text processing                           | [a-z] matches any lowercase letter from a to z                                           |
| (abc \| def) |  Matches either the pattern "abc" or "def" | Text processing