The result of a match operation. This interface contains query methods used to determine the results of a match against a regular expression. The match boundaries, groups and group boundaries, and
Matcher
Method Summary | |
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int |
end()
Returns the offset after the last character matched. |
int |
end(int group)
Returns the offset after the last character of the subsequence captured by the given group during this match. |
String |
group()
Returns the input subsequence matched by the previous match. |
String |
group(int group)
Returns the input subsequence captured by the given group during the previous match operation. |
int |
groupCount()
Returns the number of capturing groups in this match result's pattern. |
int |
start()
Returns the start index of the match. |
int |
start(int group)
Returns the start index of the subsequence captured by the given group during this match. |
Method Detail |
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int start()
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failedint start(int group)
Capturing groups are indexed from left to right, starting at one. Group zero denotes the entire pattern, so the expression m.start(0) is equivalent to m.start().
group
- The index of a capturing group in this matcher's pattern
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failed
IndexOutOfBoundsException
- If there is no capturing group in the pattern
with the given indexint end()
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failedint end(int group)
Capturing groups are indexed from left to right, starting at one. Group zero denotes the entire pattern, so the expression m.end(0) is equivalent to m.end().
group
- The index of a capturing group in this matcher's pattern
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failed
IndexOutOfBoundsException
- If there is no capturing group in the pattern
with the given indexString group()
For a matcher m with input sequence s, the expressions m.group() and s.substring(m.start(), m.end()) are equivalent.
Note that some patterns, for example a*, match the empty string. This method will return the empty string when the pattern successfully matches the empty string in the input.
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failedString group(int group)
For a matcher m, input sequence s, and group index g, the expressions m.group(g) and s.substring(m.start(g), m.end(g)) are equivalent.
Capturing groups are indexed from left to right, starting at one. Group zero denotes the entire pattern, so the expression m.group(0) is equivalent to m.group().
If the match was successful but the group specified failed to match any part of the input sequence, then null is returned. Note that some groups, for example (a*), match the empty string. This method will return the empty string when such a group successfully matches the emtpy string in the input.
group
- The index of a capturing group in this matcher's pattern
IllegalStateException
- If no match has yet been attempted,
or if the previous match operation failed
IndexOutOfBoundsException
- If there is no capturing group in the pattern
with the given indexint groupCount()
Group zero denotes the entire pattern by convention. It is not included in this count.
Any non-negative integer smaller than or equal to the value returned by this method is guaranteed to be a valid group index for this matcher.