Question

Programming: Java: Fixing errors in code help:

The errors are in square.java and rectangle.java and they both say:

constructor Shape in class Shape cannot be applied to given types;
required: no arguments
found: String
reason: actual and formal argument lists differ in length

The directions say:

The files Shape.java and TestArea.java have been finished already, YOU DONT ADD ANYTHING TO THESE TWO. According to the requirement, you need to modify in Square.java and Rectangle.java, respectively

a. Implementing constructor with no negative arguments

b. Use the protected variable “shapeName” defined in shape.java to hold the class name for each class.

c. Implementing getArea() method to return the area.

d. Implementing toString() method to print out the shape name, all class variables, and area result.

Here are all the codes and I will make bold the error part on here for the code thank you in advance!!

SQUARE.JAVA:

package shape;

public class Square extends Shape
{
private double side;
//constructor
public Square(double s)
{
   // To do 1: implement the constructor, to make sure s>=0
super("Square");
if(s>0)
this.side=s;
else
this.side=0;
}

// To do 2: calculate the area for the square
public double getArea()
{
return this.side*this.side;
}

// To do 3: return the name, side, with the area
public String toString()
{
return("Name: "+super.getName()+" Area: "+getArea());
}
}

RECTANGLE.JAVA

package shape;

public class Rectangle extends Shape
{
private double length, width;
//constructor
public Rectangle(double l, double w)
{
super("Rectangle");
if(1>0 && w>0)
{
this.length=1;
this.width=w;
}
else
{
this.length=0;
this.width=0;}
}

// To do 2: calculate the area for the square
public double getArea()
{
return this.length*width;
}

// To do 3: return the name, length, width, with the area
public String toString()
{
return("Name:"+ super.getName()+"Area: "+getArea());
}
}

SHAPE.JAVA NOT TO BE MODIFIED

package shape;

public abstract class Shape
{
protected String shapeName;
  
// abstract getArea method
public abstract double getArea();
  
public String getName()
{
return shapeName;
}
  
public String toString()
{
return String.format("%s ", getName() );
}
}

TESTAREA.JAVA NOT TO BE MODIFIED

package shape;

import java.util.Scanner;

public class TestArea
{
public static void main( String args[] )
{
Scanner input = new Scanner( System.in );

System.out.print("Input the side of the square: ");
double side = input.nextDouble();

System.out.print("Input the length of the rectangle: ");
double length = input.nextDouble();

System.out.print("Input the width of the rectangle: ");
double width = input.nextDouble();

Shape arrayOfShapes[]= new Shape[2]; //polymorphism
arrayOfShapes[0] = new Square( side );
arrayOfShapes[1] = new Rectangle(length, width );

for ( Shape shape : arrayOfShapes)
    System.out.println(shape); //invokes toString
}

}

Answer 1

//Java code

/**

Shape class does not have any constructor which takes one argument of String

the type that's why this error.

this class has protected member field shapeName so use this directly in descendent classes directly

*/

//Complete java code

package shape;
public abstract class Shape
{
    protected String shapeName;

    // abstract getArea method

    public abstract double getArea();

    public String getName()
    {
        return shapeName;
    }

    public String toString()
    {
        return String.format("%s ", getName() );
    }
}

//=====================================

package shape;

public class Rectangle extends Shape
{
    private double length, width;
    //constructor
    public Rectangle(double l, double w)
    {
       shapeName = "Rectangle";
        if(l>0 && w>0)
        {
            this.length=l;
            this.width=w;
        }
        else
        {
            this.length=0;
            this.width=0;}
    }

    // To do 2: calculate the area for the square
    public double getArea()
    {
        return length*width;
    }

    // To do 3: return the name, length, width, with the area
    public String toString()
    {
        return("Name:"+ super.getName()+" Area: "+getArea());
    }
}

//==========================================

package shape;
public class Square extends Shape
{
    private double side;
    //constructor
    public Square(double s)
    {
        // To do 1: implement the constructor, to make sure s>=0
     shapeName = "Square";
        if(s>0)
            this.side=s;
        else
            this.side=0;
    }

    // To do 2: calculate the area for the square
    public double getArea()
    {
        return this.side*this.side;
    }

    // To do 3: return the name, side, with the area
    public String toString()
    {
        return("Name: "+super.getName()+" Area: "+getArea());
    }
}

//=====================================

package shape;


import java.util.Scanner;

public class TestArea
{
    public static void main( String args[] )
    {
        Scanner input = new Scanner( System.in );

        System.out.print("Input the side of the square: ");
        double side = input.nextDouble();

        System.out.print("Input the length of the rectangle: ");
        double length = input.nextDouble();

        System.out.print("Input the width of the rectangle: ");
        double width = input.nextDouble();

        Shape arrayOfShapes[]= new Shape[2]; //polymorphism
        arrayOfShapes[0] = new Square( side );
        arrayOfShapes[1] = new Rectangle(length, width );

        for ( Shape shape : arrayOfShapes)
            System.out.println(shape); //invokes toString
    }

}

//Output

"C:\Program Files\Java\jdk1.8.0_221\bin\java. Input the side of the square: 5 Input the length of the rectangle: 4 Input the width of the rectangle: 5 Name: Square Area: 25.0 Name: Rectangle Area: 20.0 Process finished with exit code 6

//If you need any help regarding this solution....... please leave a comment........ thanks