About
The boundary matcher meta
Articles Related
List
| Symbol | Description |
|---|---|
| ^ | The beginning of a line |
| $ | The end of a line |
| \b | A word boundary |
| \B | A non-word boundary |
| \A | The beginning of the input |
| \G | The end of the previous match |
| \Z | The end of the input but for the final terminator, if any |
| \z | The end of the input |
| < | Matches the start of a word |
| > | Matches the end of a word |
Example
Word boundary
word boundary
Case 1:
- The regex: \bdog\b
- Input String to search: The dog plays in the yard
- Result: Found the text dog starting at index 4 and ending at index 7.
Case 2:
- The regex: \bdog\b
- Input string to search: The doggie plays in the yard.
- No match found.
Non-word boundary
A non-word boundary is \B.
Example 1:
- The regex: \bdog\B
- Input string to search: The dog plays in the yard.
- No match found.
Example 2:
- The regex: \bdog\B
- Input string to search: The doggie plays in the yard.
- I found the text dog starting at index 4 and ending at index 7.
End of the previous match
To require the match to occur only at the end of the previous match, use \G:
Example 1:
- The regex: dog
- Input string to search: dog dog
- Result:
- I found the text “dog” starting at index 0 and ending at index 3.
- I found the text “dog” starting at index 4 and ending at index 7.
Example 2:
- The regexp: \Gdog
- Input string to search: dog dog
- Result: I found the text dog starting at index 0 and ending at index 3.
The second example finds only one match, because the second occurrence of dog does not start at the end of the previous match.