Question

How to use \d regular expression (REGEX) in Java

Answer 1

import java.util.regex.Matcher;
import java.util.regex.Pattern;
      
public class Example {
    private static void searchREGEX(String regex, String... search) {
        Pattern pattern = Pattern.compile(regex);
         
        for (String input : search) {
            Matcher matcher = pattern.matcher(input);
     
            boolean found = false;
             
            while (matcher.find()) {
                System.out.println(String.format("Found" + " \"%s\" " + "from index %d to %d",
                                            matcher.group(), matcher.start(), matcher.end()));
                found = true;
            }
             
            System.out.println();
             
            if (!found) {
                System.out.println(String.format("%s: \"%s\" Not found\n", regex, input));
            }
        }
    }  
    public static void main(String[] args) {
        // \d  (A digit: [0-9])
        searchREGEX("\\d", "?", "1", "f35", ".", "012");
    }
}
      
     
      
/*
run:
  
\d: "?" Not found
  
Found "1" from index 0 to 1
  
Found "3" from index 1 to 2
Found "5" from index 2 to 3
  
  
\d: "." Not found
  
Found "0" from index 0 to 1
Found "1" from index 1 to 2
Found "2" from index 2 to 3
       
*/

 

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