MatchResult (Java SE 9 & JDK 9 ) (original) (raw)

• All Known Implementing Classes:
  [Matcher](../../../java/util/regex/Matcher.html "class in java.util.regex")

public interface MatchResult
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 can be seen but not modified through a MatchResult.
Since:
1.5
See Also:
Matcher

• • Method Summary

  All Methods Instance Methods Abstract Methods

  Modifier and Type	Method	Description
  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

     * #### start  
     int start​()  
     Returns the start index of the match.  
     Returns:  
     The index of the first character matched  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     * #### start  
     int start​(int group)  
     Returns the start index of the subsequence captured by the given group during this match.  
     [Capturing groups](Pattern.html#cg) 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()`.  
     Parameters:  
     `group` \- The index of a capturing group in this matcher's pattern  
     Returns:  
     The index of the first character captured by the group, or `-1` if the match was successful but the group itself did not match anything  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     `[IndexOutOfBoundsException](../../../java/lang/IndexOutOfBoundsException.html "class in java.lang")` \- If there is no capturing group in the pattern with the given index  
     * #### end  
     int end​()  
     Returns the offset after the last character matched.  
     Returns:  
     The offset after the last character matched  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     * #### end  
     int end​(int group)  
     Returns the offset after the last character of the subsequence captured by the given group during this match.  
     [Capturing groups](Pattern.html#cg) 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()`.  
     Parameters:  
     `group` \- The index of a capturing group in this matcher's pattern  
     Returns:  
     The offset after the last character captured by the group, or `-1` if the match was successful but the group itself did not match anything  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     `[IndexOutOfBoundsException](../../../java/lang/IndexOutOfBoundsException.html "class in java.lang")` \- If there is no capturing group in the pattern with the given index  
     * #### group  
     [String](../../../java/lang/String.html "class in java.lang") group​()  
     Returns the input subsequence matched by the previous match.  
      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.  
     Returns:  
     The (possibly empty) subsequence matched by the previous match, in string form  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     * #### group  
     [String](../../../java/lang/String.html "class in java.lang") group​(int group)  
     Returns the input subsequence captured by the given group during the previous match operation.  
      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](Pattern.html#cg) 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 empty string in the input.  
     Parameters:  
     `group` \- The index of a capturing group in this matcher's pattern  
     Returns:  
     The (possibly empty) subsequence captured by the group during the previous match, or `null` if the group failed to match part of the input  
     Throws:  
     `[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")` \- If no match has yet been attempted, or if the previous match operation failed  
     `[IndexOutOfBoundsException](../../../java/lang/IndexOutOfBoundsException.html "class in java.lang")` \- If there is no capturing group in the pattern with the given index  
     * #### groupCount  
     int groupCount​()  
     Returns the number of capturing groups in this match result's pattern.  
      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.  
     Returns:  
     The number of capturing groups in this matcher's pattern

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