java.time.Matcher.groupCount()方法返回此匹配器模式中的捕获组数。
int groupCount() - 声明
以下是 java.time.Matcher.groupCount()方法的声明。
public int groupCount()
int groupCount() - 返回值
此匹配器模式中的捕获组数。
int groupCount() - 示例
下面的示例显示java.time.Matcher.groupCount()方法的用法。
package com.learnfk;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MatcherDemo {
private static String REGEX = "(a*b)(foo)";
private static String INPUT = "aabfooaabfooabfoob";
public static void main(String[] args) {
Pattern pattern = Pattern.compile(REGEX);
</span><span class="com">//获取匹配器对象</span><span class="pln">
</span><span class="typ">Matcher</span><span class="pln"> matcher </span><span class="pun">=</span><span class="pln"> pattern</span><span class="pun">.</span><span class="pln">matcher</span><span class="pun">(</span><span class="pln">INPUT</span><span class="pun">);</span><span class="pln">
</span><span class="kwd">if</span><span class="pun">(</span><span class="pln">matcher</span><span class="pun">.</span><span class="pln">find</span><span class="pun">())</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
</span><span class="com">//打印此匹配器模式中的捕获组数。</span><span class="pln">
</span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="str">"Group Count: "</span><span class="pun">+</span><span class="pln">matcher</span><span class="pun">.</span><span class="pln">groupCount</span><span class="pun">());</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
}
}
让无涯教程编译并运行以上程序，这将产生以下输出-
Group Count: 2
