Thread: Actual and formal argument lists differ in length Error

Hello, i need help with my code.
I'm trying to compile a method for making phone calls but i get an error that i'm not sure why. (BlueJ)


Here is the code connected with this method:

    public int getPhoneNumber()
    {
        int phoneNumber = Integer.parseInt(phoneNoField.getText());
        if (phoneNumber == -1)
        {
            JOptionPane.showMessageDialog(frame, "Please use a positive number",
                "Attention", JOptionPane.WARNING_MESSAGE);
        }
        return phoneNumber;
    }
 
    public int getDuration()
    {
        int theDuration = Integer.parseInt(durationField.getText());
        if (theDuration == -1)
        {
            JOptionPane.showMessageDialog(frame, "Please enter a positive number",
                "Attention", JOptionPane.WARNING_MESSAGE);
        }
        return theDuration;
    }
 
    public int getDisplayNum()
    {
        int getDisplayNum = -1;
        try {
            getDisplayNum = Integer.parseInt(displayNoField.getText())-1;
            if(getDisplayNum < 0){
                JOptionPane.showMessageDialog(frame, "Please enter a number greater than 0",
                    "Attention", JOptionPane.WARNING_MESSAGE);
            }
        }
        catch(NumberFormatException e){
            JOptionPane.showMessageDialog(frame, "Please enter an integer",
                "Attention", JOptionPane.WARNING_MESSAGE);
        }
        return getDisplayNum;
    }
 
    public void phoneCall()
    {
        Gadget mobPhone = Devices.get(getDisplayNum());
        if (getDisplayNum() != -1 && mobPhone instanceof Phone)
        {
            Phone phone = (Phone) Devices.get(getDisplayNum());
            phone.phoneCall(getDisplayNum(), getDuration());
        }
        else {
            JOptionPane.showMessageDialog(frame, "This isn't a Mobile Phone",
                "Attention", JOptionPane.WARNING_MESSAGE);
        }
    }

Please let me know if you need more info
Thank you

It tells you right there. The phoneCall method does not expect any arguments. But you are calling it like this.

phone.phoneCall(getDisplayNum(), getDuration());

It should be called like this.

phone.phoneCall();

Regards,
Jim

I am unfamiliar with your classes but some of this looks strange.

 public void phoneCall()
    {
        Gadget mobPhone = Devices.get(getDisplayNum());
        if (getDisplayNum() != -1 && mobPhone instanceof Phone)
        {
            Phone phone = (Phone) Devices.get(getDisplayNum());
            phone.phoneCall(getDisplayNum(), getDuration());
        }
        else {
            JOptionPane.showMessageDialog(frame, "This isn't a Mobile Phone",
                "Attention", JOptionPane.WARNING_MESSAGE);
        }
    }

Why do you call Devices.get(DisplayNum()) twice? And if mobPhone was an instance of Phone, you could just
use what was returned.

Also, I presume that the method you are in, (i.e. phoneCall()), is different that the phone.phoneCall().

Regards,
Jim

You don't need to pass getDisplayNum() and getDuration() to phoneCall() as what Jim said.