子表达式/元字符“()”对正则表达式进行分组并记住匹配的文本。
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main( String args[] ) { String input = "Hello how are you welcome to Nhooo"; String regex = "H(ell|ow)"; //编译正则表达式 Pattern pattern = Pattern.compile(regex); //检索匹配器对象 Matcher matcher = pattern.matcher(input); if(matcher.find()) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } }
输出结果
Match found
在以下示例中,我们尝试匹配其中带有数字的句子-
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class PatternExample { public static void main(String[] args) { System.out.println("Enter input string: "); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); //使用组的正则表达式 String regex = "(?:.*)(\\d+)(.*)"; //创建一个模式对象 Pattern pattern = Pattern.compile(regex); //创建一个Matcher对象 Matcher matcher = pattern.matcher(input); boolean bool = matcher.matches(); if(bool) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } }
输出结果
Enter input string: This is a 5363 test string Match found