package example6_2;

import javax.swing.JOptionPane;

public class JOptionPaneRelief {
    public static void main(String[] args) {
        // REPLACE THIS PART WITH Double.parseDouble()
        // and try/catch
        // No need to loop.
        // You can just catch "Exception"

        String defaultMessage = "How many kg of food?";
        String updatedMessage = defaultMessage;

        double foodKg = -1;
        while(foodKg <= 0) { // until: input valid: foodKg > 0
            String line = JOptionPane.showInputDialog(updatedMessage);
            try {
                foodKg = Double.parseDouble(line);
            } catch(Throwable e) {
//            } catch(Exception e) { // alternative
                updatedMessage = defaultMessage + " Please enter a number (may have decimal part)";
            }
        }

        System.out.println("You entered:"+foodKg);

    }
}