예제가 있는 Java의 패턴 COMMENTS 필드

Pattern 클래스의 COMMENTS 필드는 패턴에 공백과 주석을 허용합니다. 이것을 compile() 메서드에 대한 플래그 값으로 사용하면 주어진 패턴에서 공백과 #로 시작하는 주석이 무시됩니다.

예시 1

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class COMMENTES_Example {
   public static void main( String args[] ) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter input data: ");
      String input = sc.nextLine();
      //Regular expression to find digits
      String regex = "\\d #ignore this comment\n";
      //Compiling the regular expression
      Pattern pattern = Pattern.compile(regex, Pattern.COMMENTS);
      //Retrieving the matcher object
      Matcher matcher = pattern.matcher(input);
      int count = 0;
      String result = "";
      while (matcher.find()) {
         count++;
         result = result+matcher.group();
      }
      System.out.println("Number of digits in the given text: "+count);
   }
}

출력

Enter input data:
sample1 text2 with3 numbers4 in5 between6
Number of digits in the given text: 6

예시 2

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class COMMENTES_Example {
   public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter your name: ");
      String name = sc.nextLine();
      System.out.println("Enter your Date of birth: ");
      String dob = sc.nextLine();
      //Regular expression to accept date in MM-DD-YYY format
      String regex = "^(1[0-2]|0[1-9])/
         # For Month\n" + "(3[01]|[12][0-9]|0[1-9])/
         # For Date\n" + "[0-9]{4}$ # For Year";
      //Creating a Pattern object
      Pattern pattern = Pattern.compile(regex, Pattern.COMMENTS);
      //Creating a Matcher object
      Matcher matcher = pattern.matcher(dob);
      boolean result = matcher.matches();
      if(result) {
         System.out.println("Given date of birth is valid");
      } else {
         System.out.println("Given date of birth is not valid");
      }
   }
}

출력

Enter your name:
Krishna
Enter your Date of birth:
09/26/1989
Given date of birth is valid