B5 Day 19 number compare

package mrb5week4;
import java.util.Scanner;

public class Day19B {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double num1 = 0;
        double num2 = 0;
        double numTotal = 0;
        String op = "+";
        String userInput = "";

        System.out.print("num1: ");
        userInput = sc.nextLine();
        if (isNumeric(userInput)) {
            num1 = Double.parseDouble(userInput);
        }
        System.out.print("operator: ");
        op = sc.nextLine();
        System.out.print("num2: ");
        userInput = sc.nextLine();
        if (isNumeric(userInput)) {
            num2 = Double.parseDouble(userInput);
        }
        System.out.println(num1 + " " + op + " " + num2);
    }

    public static boolean isNumeric(String strNum) {
        if (strNum == null) {
            return false;
        }
        try {
            double d = Double.parseDouble(strNum);
        } catch (NumberFormatException nfe) {
            return false;
        }
        return true;
    }
}