NumberFormatException

package taoshiflex.lab8;

import java.util.Scanner;

public class Lab8 {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        
        System.out.print("Enter a binary string: ");
        String binaryString = scan.nextLine();

        try {
            int decimalValue = bin2Dec(binaryString);
            System.out.println("Decimal value: " + decimalValue);
        } 
        catch (NumberFormatException e) {
            System.out.println("Error: " + e.getMessage());
        }

        scan.close();
    }
    
    public static int bin2Dec(String binaryString) throws NumberFormatException {
      // Check if the string is a valid binary string
        for (char c : binaryString.toCharArray()) {
            if (c != '0' && c != '1') {
                throw new NumberFormatException("Input is not a binary string.");
            }
        }

        // Convert binary string to decimal
        return Integer.parseInt(binaryString, 2);
    }

}