illegal start of type!

[dean lin]

Dear All

Please help me ! How can I solve this problem

After complier this code I got this error message

C:\Dean>javac Menu3.java
Menu3.java:62: illegal start of type
while(true){
^
Menu3.java:102: class, interface, or enum expected
}
^
2 errors

Thank you!

   import java.io.*;

public class Menu3 {
	public static void main(String[] args) throws IOException{
        class Rectangle {
    int length;
    int width;

    Rectangle(){
	length = 8;
	width = 4;
    }	

    Rectangle(int length, int width){
	this.length = length;
	this.width = width;
    }

    Rectangle(Rectangle obj){
	this.length = obj.length;
	this.width = obj.width;
    }

    void showLW(){
	System.out.println("length: " + length + "\nwidth: " + width);
    }

    double getArea(){
	return Math.sqrt(3)/4*Math.pow(length,2);
    }

    void drawRect(){
	
    final int n = Integer.parseInt(args[0]);
	
	for (int i=1 ; i < n  ;i++  ) {
           for (int j=n-i ; j > 1 ;j-- )  
                 System.out.print( " " );

          for (int j=1 ; j < i ;j++ )

            System.out.print( "* " );
            System.out.println(); 
	}

	}
    
}

	
	
Rectangle r1 = new Rectangle(8,4);//new a object

		boolean exit = false;
		
		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));

		while(true){
			int choice;

			System.out.println("\n**** Menu ****\n\n");
			System.out.println("(1) Choice One.\n");
			System.out.println("(2) Choice Two.\n");
			System.out.println("(3) Choice Three.\n");
			System.out.println("(4) Quit.\n\n");
			System.out.println(":");

			
			choice = Integer.parseInt(stdin.readLine());

			switch(choice){
				case 1:
					
					System.out.println("length: " + r1.length + "\nwidth: " + r1.width);
					
                                        	
					break;
				case 2:
					
					System.out.println("\nwidth: " + r1.getArea());
					break;
				case 3:
	                                System.out.println("\nwidth: " + r1.drawRect());			
					break;
				case 4:
					exit = true;
					break;
				default:
					System.out.println("Please select again!\n");
					break;
			} // end of switch

			if(exit) break;
		}
	}
}
 

[jittu goud]

final int n = Integer.parseInt(args[0]);  

you are referring a static main method argument from a nonstatic innner class...which is not allowed

the best way is read the arguments before the innerclass in to a final variable.........and use it in the code

System.out.println("\nwidth: " + r1.drawRect());  

r1.drawRect() returns a void ...so what do you want to print using a method which returns a void...

you can skip the print statement...and use the r1.drawRect(); directly

[salvin francis]

this is the error message i got when compiled:

javac Menu3.java
Menu3.java:35: local variable args is accessed from within inner class; needs to be declared final
				final int n = Integer.parseInt(args[0]);   
                                                               ^
Menu3.java:75: 'void' type not allowed here
					System.out.println("\nwidth: " + r1.drawRect());               
                                                           ^
2 errors

The first error is self explainatory,

The second error means : what do you expect to be appended to string? the return type of the function is void.

Bad programming practices:

Defining a class in main
No proper indentations.
Conditional Statements, Loops whose statements are not in braces

[dean lin]

Dear All

Thank you very much for your suggestion

I modify my code as below it can work now

But still don't understand this hint

Bad programming practices:

Defining a class in main
No proper indentations.
Conditional Statements, Loops whose statements are not in braces

Would you please explain it more detail or please give me some document about it

I will try to understand it

import java.io.*;

public class Retangle {
public static void main(String[] args) throws IOException{
  class Rectangle {
    int length;
    int width;

    Rectangle(){
        length = 8;
	width = 4;
    }	

    Rectangle(int length, int width){
	this.length = length;
	this.width = width;
    }

    Rectangle(Rectangle obj){
	this.length = obj.length;
	this.width = obj.width;
    }

    
    void showLW(){
	System.out.println("length: " + length + "\nwidth: " + width);
    }

    double getArea(){
	return Math.sqrt(3)/4*Math.pow(length,2);
    }

    void drawRect(){
	
    //final int n = Integer.parseInt(args[0]);
	
	for (int i=0 ; i < width  ;i++  ) {
           for (int j=0 ; j < length  ;j++ )  
              
            System.out.print( "* " );
            System.out.println('\n'); 
	}

	}
    
    
    }
	

	
	
Rectangle r1 = new Rectangle(8,4);//new a object

		boolean exit = false;
		
		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));

		while(true){
			int choice;

			System.out.println("\n**** Menu ****\n\n");
			System.out.println("(1) Choice One.\n");
			System.out.println("(2) Choice Two.\n");
			System.out.println("(3) Choice Three.\n");
			System.out.println("(4) Quit.\n\n");
			System.out.println(":");

		
			choice = Integer.parseInt(stdin.readLine());

			switch(choice){
				case 1:
					//System.out.println("\nTask One a!");
					System.out.println("length: " + r1.length + "\nwidth: " + r1.width);
					//System.out.println("\nTask One b!");
                                        	
					break;
				case 2:
					//System.out.println("\nTask Two!!");
					System.out.println("\nwidth: " + r1.getArea());
					break;
				case 3:
	                                r1.drawRect();			
					break;
				case 4:
					exit = true;
					break;
				default:
					System.out.println("Please select again!\n");
					break;
			} // end of switch

			if(exit) break;
		}
	
	}

	}

    

[Campbell Ritchie]

The Rectangle class ought to be in a file of its own.
For the other things, have a look at our Chicken Coop.