Pattern flags() method in Java with Examples

The flags() method of the Pattern class in Java is used to return the pattern’s match flags. The Match flags are a bit mask that may include CASE_INSENSITIVE, MULTILINE, DOTALL, UNICODE_CASE, CANON_EQ, UNIX_LINES, LITERAL, UNICODE_CHARACTER_CLASS and COMMENTS Flags. 

Syntax:

public int flags()

Parameters: This method does not accepts any parameters. 

Return Value: This method returns the pattern’s match flag. 

Below programs illustrate the flags() method: 

Program 1:

Java

// Java program to demonstrate
// Pattern.flags() method

import java.util.regex.*;

public class GFG {
    public static void main(String[] args)
    {
        // create a REGEX String
        String REGEX = "(.*)(for)(.*)?";

        // create the string
        // in which you want to search
        String actualString
            = "code of Machine";

        // compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(REGEX,
                         Pattern.CASE_INSENSITIVE);

        // find the flag of pattern
        int flag = pattern.flags();

        System.out.println("Pattern's match flag = "
                           + flag);
    }
}

Output:

Pattern's match flag = 2

Program 2:

Java

// Java program to demonstrate
// Pattern.flags method

import java.util.regex.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a REGEX String
        String REGEX = "(.*)(ee)(.*)?";

        // create the string
        // in which you want to search
        String actualString
            = "geeks";

        // compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(REGEX,
                                 Pattern.MULTILINE);

        // find the flag of pattern
        int flag = pattern.flags();

        System.out.println("Pattern's match flag = "
                           + flag);
    }
}

Output:

Pattern's match flag = 8

References: https://docs.oracle.com/javase/10/docs/api/java/util/regex/Pattern.html#flags()