Pattern compile(String) method in Java with Examples

Thw compile(String) method of the Pattern class in Java is used to create a pattern from the regular expression passed as parameter to method. Whenever you need to match a text against a regular expression pattern more than one time, create a Pattern instance using the Pattern.compile() method.

Syntax:

public static Pattern compile(String regex)

Parameters: This method accepts one single parameter regex which represents the given regular expression compiled into a pattern.



Return Value: This method returns the pattern complied from the regex passed to the method as a parameter.

Exception: This method throws following exception:

  • PatternSyntaxException: This exception is thrown if the expression’s syntax is invalid.

Below programs illustrate the compile(String) method:
Program 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

// 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 = ".*www.*";
  
        // creare the string
        // in which you want to search
        String actualString
            = "www.geeksforgeeks.org";
  
        // compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(REGEX);
  
        // get a matcher object from pattern
        Matcher matcher = pattern.matcher(actualString);
  
        // check whether Regex string is
        // found in actualString or not
        boolean matches = matcher.matches();
  
        System.out.println("actualString "
                           + "contains REGEX = "
                           + matches);
    }
}

chevron_right


Output:

actualString contains REGEX = true

Program 2:

filter_none

edit
close

play_arrow

link
brightness_4
code

// 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 = "brave";
  
        // creare the string
        // in which you want to search
        String actualString
            = "Cat is cute";
  
        // compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(REGEX);
  
        // check whether Regex string is
        // found in actualString or not
        boolean matches = pattern
                              .matcher(actualString)
                              .matches();
  
        System.out.println("actualString "
                           + "contains REGEX = "
                           + matches);
    }
}

chevron_right


Output:

actualString contains REGEX = false

Reference: https://docs.oracle.com/javase/10/docs/api/java/util/regex/Pattern.html#compile(java.lang.String)



My Personal Notes arrow_drop_up

I am a Developer I love to code and bring my ideas alive

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.