Regular Expression Pattern
Sample Regex Example:- /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/
Sample Regex Example:- /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/
Find each character attribute information of above expression below.
| Character | Description |
|---|---|
| / .. / | All regular expressions start and end with forward slashes. |
| ^ | Matches the beginning of the string or line. |
| \w+ | Matches one or more word characters including the underscore. Equivalent to [A-Za-z0-9_]. |
| [\.-] | \ Indicates that the next character is special and not to be interpreted literally. .- matches character . or -. |
| ? | Matches the previous character 0 or 1 time. Here previous character is [.-]. |
| \w+ | Matches 1 or more word characters including the underscore. Equivalent to [A-Za-z0-9_]. |
| * | Matches the previous character 0 or more times. |
| ([.-]?\w+)* | Matches 0 or more occurrences of [.-]?\w+. |
| \w+([.-]?\w+)* | The sub-expression \w+([.-]?\w+)* is used to match the username in the email. It begins with at least one or more word characters including the underscore, equivalent to [A-Za-z0-9_]. , followed by . or - and . or - must follow by a word character (A-Za-z0-9_). |
| @ | It matches only @ character. |
| \w+([.-]?\w+)* | It matches the domain name with the same pattern of user name described above.. |
| \.\w{2,3} | It matches a . followed by two or three word characters, e.g., .edu, .org, .com, .uk, .us, .co etc. |
| + | The + sign specifies that the above sub-expression shall occur one or more times, e.g., .com, .co.us, .edu.uk etc. |
| $ | Matches the end of the string or line. |
Note: If you want to work on 4 digit domain, for example, .info or .edxu or .tiff then you must change w{2,3} to w{2,4}.
