re+ 元字符在 Java 中的正则表达式


子表达式/元字符 “re+” 匹配前面的表达式的出现一次或多次。

示例 1

import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexExample {
   public static void main( String args[] ) {
      String regex = "aabc+";
      String input = "aabcabcaabcabbcaabcbcaabc";
      Pattern p = Pattern.compile(regex);
      Matcher m = p.matcher(input);
      int count = 0;
      while(m.find()) {
         count++;
      }
      System.out.println("Number of matches: "+count);
   }
}

输出

Number of matches: 4

示例 2

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Test {
   public static void main( String args[] ) {
      String regex = "[0-9]+";
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter an input string: ");
      String input = sc.nextLine();
      //Creating a Pattern object
      Pattern p = Pattern.compile(regex);
      //Creating a Matcher object
      Matcher m = p.matcher(input);
      if(m.find()) {
         System.out.println("Given input contains digits");
      } else {
         System.out.println("Given input doesn't contain digits");
      }
   }
}

输出 1

Enter an input string:
sample text
Given input doesn't contain digits

输出 2

Enter an input string:
sample data 464
Given input contains digits

更新于:19-Nov-2019

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