public class Square {
 

  private double side;
  private double perimeter;
  private double area;
  
  
  
 
  public Square(int x){
   
  side = side;
   
  }
  
  public double getSide(){
   
    
    return side;
  }
  
  
 
  public String toString(){
    String s = side + "---";
    s = s + side;
    s = s + area;
    s = s + perimeter;
  return s; 
    
  }
  
  
  public double calculateArea(){
    
    return side*side;
  }
  

  public double calculatePerimeter(){
   
    return side*4;
  }
}

perimeter = calculatePerimeter();
area = calculateArea();

public class Square {
    private double side;
    //private double perimeter; //not used
    //private double area; //not used
    
    public Square(int x){
        side = x; //X: side = side; //this does nothing
    }
    
    public String dataToString(){ //X: toString(){ //don't use "toString()," it can end up overriding a class method
        String s = ""; //X: "---" //start with it blank
        String endl = "\n"; //new line variable
        s += endl + "Side:      " + getSide(); //X:+ side; //you never assigned a value to this variable, that's why it appeared as a 0
        s += endl + "Area:      " + getArea();  //X:+ area; //you never assigned a value to this variable, that's why it appeared as a 0
        s += endl + "Perimeter: " + getPerimeter(); //X:+ perimeter; //you never assigned a value to this variable, that's why it appeared as a 0
        return s;
    }

    public double getSide(){
        return side;
    }
    
    public double getArea(){ //X:calculateArea(){ //stick with the root "get", consistency makes usage easier. it is also less to type
        return side*side;
    }
    
    public double getPerimeter(){ //X:calculatePerimeter(){ //stick with the root "get", consistency makes usage easier. it is also less to type
        return side*4;
    }
}

//import the scanner
import java.util.Scanner;

public class TestSquare{
    //create variables
    public static Scanner reader = new Scanner(System.in);
    public static int num;
    
    public static void main(String[] args){
        //tell the user what to do
        System.out.print("Enter the measurement of square side: ");
        //get user data
        num = reader.nextInt();
        //instantiate the class
        Square square = new Square(num);
        //use the classes output method
        System.out.print(square.dataToString());
    }
}