Debugging: Cannot Find Symbol

[whitedragon551]

I am debugging some code and for the love of god can not figure out why Im getting this error. The code is:

// DebugThirteen1
// Creates a frame with a specified size
// Twice as tall as wide
import javax.swing.*;
public class DebugThirteen1 extends JFrame
{
   public DebugThirteen1(int size)
   {
	super("This is my frame");
	size = 200;  //Set size
	setSize(size, size * 2);
	setVisible(true); //Added this line to set frame to visible
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//Missing period between JFrame and EXIT
   }
   public static void main(String[] args)
   {
   DebugThirteen1 frame = new DebugThirteen1(); //Missing word new
   } 
}

The error is:

C:\Users\Tyler\Documents\School Work\CIS280\Project 9>javac DebugThirteen1.java
DebugThirteen1.java:17: cannot find symbol
symbol : constructor DebugThirteen1()
location: class DebugThirteen1
JFrame DebugThirteen1 = new DebugThirteen1(); //Missing word new
^
1 error

I cant figure out why this error is coming up.

[wsaryada]

You receive the error because you don't have a default constructor in you class. Default constructor is constructor without parameters. Because of this you can call the default constructor using the new operator to create an instance of that class.

In your class you only have a constructor that accept a single parameter with the integer type. That's mean when creating a new instance you have to call this constructor. You should do:

    DebugThirteen1 frame = new DebugThirteen1(100);

Instead of:

    DebugThirteen1 frame = new DebugThirteen1();

Which will produce an error because the constructor is not available.

[whitedragon551]

Thank you for the explanation. That makes sense. So how would I go about getting rid of the necessary int argument in my Main? Would I just move size to the class?

[wsaryada]

You can always provide a default constructor in your class. And then define the default size of the frame in this constructor. So when you create a new instance using default constructor it will always use the default frame size.

[whitedragon551]

This is what I did so I only had to define size 1 time rather than through an argument as well.

// DebugThirteen1
// Creates a frame with a specified size
// Twice as tall as wide
import javax.swing.*;
public class DebugThirteen1 extends JFrame
{
size = 200;  //Set size
   public DebugThirteen1(int size)
   {
    super("This is my frame");
  
    setSize(size, size * 2);
    setVisible(true); //Added this line to set frame to visible
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//Missing period between JFrame and EXIT
   }
   public static void main(String[] args)
   {
   DebugThirteen1 frame = new DebugThirteen1(); //Missing word new
   }
}