The java.lang.String class gives a considerable measure of methods to deal with a string. By the assistance of these methods, one can perform operations on the string like trimming, concatenating, converting and comparing. We can extract the numbers from a given string by using the replaceAll() method of a String class.
Example
import java.util.Scanner;
public class StringExtractTest {
public static void main(String[] args) {
String input;
String numbers;
Scanner scanner = new Scanner(System.in);
System.out.print(" Please enter a string from the keyboard that contains numbers: ");
input = scanner.nextLine();
numbers = input.replaceAll("[^0-9]", "");
System.out.println("The Numbers are: " + numbers);
}
}Output
Please enter a string from the keyboard that contains numbers: Welcome to Tutorials Point 1234567890 The Numbers are: 1234567890