Java Pattern flags()方法及示例

Java中 Pattern 类的 flags() 方法是用来返回模式的匹配标志的。匹配标志是一个位掩码，可能包括CASE_INSENSITIVE, MULTILINE, DOTALL, UNICODE_CASE, CANON_EQ, UNIX_LINES, LITERAL, UNICODE_CHARACTER_CLASS和COMMENTS标志。

语法

public int flags()

参数： 该方法不接受任何参数。

返回值： 该方法返回模式的匹配标志。

下面的程序说明了flags()方法。

程序1 :

// 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);
    }
}

输出:

Pattern's match flag = 2

程序2

// Java program to demonstrate
// Pattern.compile 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);
    }
}

输出: