Regular Expression re+ Metacharacter in Java

The subexpression/metacharacter “re+” matches one or more occurrences of the preceding expression.

Example 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);    } }

Output

Number of matches: 4

Example 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");       }    } }

Output 1

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

Output 2

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