The metacharacter "\\s" matches the white space characters in the given string.
Example 1
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Example {
public static void main(String args[]) {
//Reading String from user
System.out.println("Enter a String");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
String regex = "\\s";
//Compiling the regular expression
Pattern pattern = Pattern.compile(regex);
//Retrieving the matcher object
Matcher matcher = pattern.matcher(input);
int count = 0;
while(matcher.find()) {
count++;
}
System.out.println("Number of spaces: "+count);
}
}Output
Enter a String Hello how are you welcome to tutorialspoint Number of spaces: 6
Example 2
import java.util.Scanner;
public class RegexExample {
public static void main( String args[] ) {
//regular expression
String regex = "\\s+";
System.out.println("Enter input value: ");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
String result = input.replaceAll(regex, "");
System.out.println("Result: "+result);
}
}Output
Enter input value: hello how are you Result: hellohowareyou