Pattern matcher(CharSequence) method in Java with Examples

The matcher(CharSequence) method of the Pattern class used to generate a matcher that will helpful to match the given input as parameter to method against this pattern. The Pattern.matcher() method is very helpful when we need to check a pattern against a text a single time, and the default settings of the Pattern class are appropriate.

Syntax:

public Matcher matcher(CharSequence input)

Parameters: This method accepts a single parameter input which represents the character sequence to be matched.

Return Value: This method returns a new matcher for this pattern.

Below programs illustrate the matcher(CharSequence) method:

Program 1:

Java

// Java program to demonstrate
// Pattern.matcher(CharSequence) 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
            = "geeksforgeeks";
 
        // create a Pattern
        Pattern pattern = Pattern.compile(REGEX);
 
        // get a matcher object
        Matcher matcher = pattern.matcher(actualString);
 
        // print values if match found
        boolean matchfound = false;
        while (matcher.find()) {
            System.out.println("found the Regex in text:"
                               + matcher.group()
                               + " starting index:" + matcher.start()
                               + " and ending index:"
                               + matcher.end());
 
            matchfound = true;
        }
        if (!matchfound) {
            System.out.println("No match found for Regex.");
        }
    }
}

Output:

found the Regex in text:geeksforgeeks starting index:0 and ending index:13

Program 2:

Java

// Java program to demonstrate
// Pattern.matcher(CharSequence) method
 
import java.util.regex.*;
 
public class GFG {
    public static void main(String[] args)
    {
        // create a REGEX String
        String REGEX = "(.*)(welcome)(.*)?";
 
        // create the string
        // in which you want to search
        String actualString
            = "geeksforgeeks";
 
        // create a Pattern
        Pattern pattern = Pattern.compile(REGEX);
 
        // get a matcher object
        Matcher matcher = pattern.matcher(actualString);
 
        // print values if match found
        boolean matchfound = false;
        while (matcher.find()) {
            System.out.println("match found");
            matchfound = true;
        }
        if (!matchfound) {
            System.out.println("No match found");
        }
    }
}