The \b meta character in Java regular expressions matches the word boundaries Therefore to find a particular word from the given input text specify the required word within the word boundaries in the regular expressions as −
"\\brequired word\\b";
Example 1
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MachingWordExample1 { public static void main( String args[] ) { //Reading string value Scanner sc = new Scanner(System.in); System.out.println("Enter input string"); String input = sc.next(); //Regular expression to find digits String regex = "\\bhello\\b"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); if(matcher.find()) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } }
Output
Enter input string hello welcome to Tutorialspoint Match found
Example 2
import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatcherExample2 { public static void main( String args[] ) { String input = "This is sample text \n " + "This is second line " + "This is third line"; String regex = "\\bsecond\\b"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); if(matcher.find()) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } }
Output
Match found