CODEWITHSUNDEEP
javaclassvariables
Mihailo Jovanovic
Mihailo Jovanovic

Reputation: 1

Can I set class "property" based on other property?

I want to set property of class based on this first switch. If vrsta (eng. type) is krug (circle) I want to have its diameter (r) as property of its type Figura (eng. Figure), if it is pravouganonik(eng. rectangle) I want to have its sides: a and b, and if it kvadrat(eng. square) I want to have its side value (str). How can I fix my switch, it gives me compile error. Illegal start of type on switch(vrsta){, it gives me expected on same line, orphaned case on case "krug". Thank you so much!

import java.util.Scanner;

class Figura{
String boja,vrsta;
Double povr;

switch (vrsta){
    case "krug":
        Double r;
        break;
    case "pravougaonik":
        Double a,b;
        break;
    case "kvadrat":
        Double str;
        break;
}

Figura(String b, String v){
    Scanner sc=new Scanner(System.in);
    boja=b;
    vrsta=v;
    switch (vrsta){
        case "krug":
            r=sc.nextDouble();
            povr=r*r*3.14;
            break;
        case "pravougaonik":
            a=sc.nextDouble();
            b=sc.nextDouble();
            povr=a*b;
            break;
        case "kvadrat":
            str=sc.nextDouble();
            povr=str*str;
            break;
    }
}

public static void main(String args[]){
    Scanner sc=new Scanner(System.in);
    Figura f1=new Figura(sc.nextLine(),sc.nextLine());
    System.out.println(f1.povr);
}
}

Upvotes: 0

Views: 78

Answers (1)

Rajeev Singh
Rajeev Singh

Reputation: 3332

The error compile error. Illegal start of type on switch(vrsta) is raised because it doesn't follow the convention for defining members. Instead, it should be wrapped inside a member function.

A member should be defined like this

class A {
    modifiers type name;
}

A simple solution for this problem is to use inheritance. Create a base class Figure, and create other child classes Circle, Square, Rectangle from it.

class Figure {
    // base class
}

class Circle extends Figure {
    double radius;
}

class Rectangle extends Figure {
    double length;
    double width;
}

class Square extends Figure {
    double side;
}

In main you can create the object of the Class that you need

public static void main(String[] args) {
    Figure f;
    int type = 1; // set type as required

    switch(type) {
        case 1:
            f = new Circle();
            break;
        case 2:
            f = new Rectangle();
            break;
        case 3:
            f = new Square();
            break;
        default:
            f = new Figure();
    }
}

Upvotes: 1

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