if-statement inside a try-catch block returns "Infinite"-CodePudding

First of all i'm new to programming and just finished the Course on SoloLearn about C#. I do understand the core principal of try-catch blocks but i can't figure out how to correctly implement this in to my code(code shown below).

class Program
{
    static void Main(string[] args)
    {   //create object of Class Calculator
        Calculator calc = new Calculator();

        //take user input and store in num1 and print it to screen
        try{
            double num1 = Convert.ToInt32(Console.ReadLine());
            Console.Write("\nnumber1: "   num1);
            double num2 = Convert.ToInt32(Console.ReadLine());
            Console.Write("\nnumber2: "   num2);
        
            //take operator as input and print it to screen
            string operand = Console.ReadLine();
            Console.Write("\noperator: "   operand);

            //check if operator from user input is equal to one of the 4 calculation methods in Calculator Class
            Console.Write("\nresult: ");
            if(operand == " "){
            Console.WriteLine(calc.Addition(num1, num2));
            }
            else if(operand == "-"){
            Console.WriteLine(calc.Subtraction(num1, num2));
            }
            else if(operand == "*"){
            Console.WriteLine(calc.Multiplication(num1, num2));
            }
            else{
            Console.WriteLine(calc.Division(num1, num2));
            }
        }
        catch(DivideByZeroException){
            Console.WriteLine("can't divide by zero");
        }
        catch(Exception e){
            Console.WriteLine("An error occurred. Only integers are allowed!");
        } 
    }
}//class Calculator with methods for 4 simple calculations
class Calculator{
    private double number1;
    private double number2;
    private double res;

    public double Addition(double num1, double num2){
        this.number1 = num1;
        this.number2 = num2;
        this.res = num1   num2;
        return res;
    }
    public double Subtraction(double num1, double num2){
        this.number1 = num1;
        this.number2 = num2;
        this.res = num1 - num2;
        return res;
    }
    public double Multiplication(double num1, double num2){
        this.number1 = num1;
        this.number2 = num2;
        this.res = num1 * num2;
        return res;
    }
    public double Division(double num1, double num2){
        this.number1 = num1;
        this.number2 = num2;
        this.res = num1 / num2;
        return res;
    }
}

So i want my simple calculator to handle the exception "DivideByZero" and "Exception e" -> if the input was not an integer.

When i test the DivideByZero Exception with an example input of 4/0, the programm returns "Infinite" as a result instead of the code from the catch block.

I guess the "Infinite" result comes from the if-statements inside the try-catch block but i'm not sure.

I searched multiple sites, similar posts on stackoverflow and read the microsoft documentation for c# about try-catch blocks but i just can't figure it out.

Sorry if my code sample is too big but i think this is the best way to understand my mess of code.

Thank you in advance for the quick reply !

CodePudding user response：

There is nothing wrong with your try catch. If you divide a double by zero, you don't get an exception. You get Double.PositiveInfinity as result in your case. The DivideByZeroException is only thrown for integer or decimal data types.

CodePudding user response：

Change fragment

 else {
   Console.WriteLine(calc.Division(num1, num2));
 }

into

 else {
  Console.WriteLine(num2 != 0 
     ? $"{calc.Division(num1, num2)}" 
     :  "can't divide by zero");
}

Since floating point division doesn't throw exception but returns NaN, PositiveInfinity and NegativeInfinity:

 0.0 / 0.0 == double.NaN
 1.0 / 0.0 == double.PositiveInifinity
-1.0 / 0.0 == double.NegativeInfinity