Java MatchResult groupCount()用法及代码示例

MatchResult Inteface的groupCount()方法用于获取此匹配器模式中的捕获组数。此方法返回一个整数值，该整数值是匹配此匹配器时找到的组数。

用法:

public int groupCount()

参数：此方法不带任何参数。

返回值：此方法返回此匹配器模式中的捕获组数。

下面的示例说明MatchResult.groupCount()方法：

示例1:

// Java code to illustrate groupCount() method 
  
import java.util.regex.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Get the regex to be checked 
        String regex = "(Geeks)"; 
  
        // Create a pattern from regex 
        Pattern pattern 
            = Pattern.compile(regex); 
  
        // Get the String to be matched 
        String stringToBeMatched 
            = " GeeksForGeeks Geeks for For Geeks Geek"; 
  
        // Create a matcher for the input String 
        MatchResult matcher 
            = pattern 
                  .matcher(stringToBeMatched); 
  
        // Get the number of capturing groups 
        // using groupCount() method 
        System.out.println(matcher.groupCount()); 
    } 
}

输出：

示例2:

// Java code to illustrate groupCount() method 
  
import java.util.regex.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Get the regex to be checked 
        String regex = "GFG"; 
  
        // Create a pattern from regex 
        Pattern pattern 
            = Pattern.compile(regex); 
  
        // Get the String to be matched 
        String stringToBeMatched 
            = "FGF GF FG FGF"; 
  
        // Create a matcher for the input String 
        MatchResult matcher 
            = pattern 
                  .matcher(stringToBeMatched); 
  
        // Get the number of capturing groups 
        // using groupCount() method 
        System.out.println(matcher.groupCount()); 
    } 
}

输出：

参考： https://docs.oracle.com/javase/9/docs/api/java/util/regex/Matcher.html#groupCount–

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注：本文由纯净天空筛选整理自Kirti_Mangal大神的英文原创作品 MatchResult groupCount() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。