After using a explicit throw keyword ,why the other implicit throw is not working in case of multiple catch statement?

Question

In this programe MyclassEx is child class of Exception(java.lang.Exception).we create user define exception.In the class contain a parameterized constructor who pass its argument to super class that is Exception class.outside this class I declare another class SimpleThrow.here i take input of two variable x,y of double type.and Z is divident of x,y.if i take y as zero it should throw the control to catch(ArithmeticException e)block.but it do not throw any of the catch block except the user defined Exception i.e,MyclassEx.How can I make all catch block active with the Myclass exception?

import java.lang.Exception;
import java.util.*;
class MyclassEx extends Exception{
    MyclassEx(String msg)
    {
        super(msg);
        System.out.println(msg);
    }
}
public class SimpleThrow
{
    public static void main(String[] args)
    {
        
        try
        {
            double x=0,y=0,z=0;
            Scanner sc=new Scanner(System.in);
            System.out.print("Enter two numbers:");
            x=sc.nextDouble();
            y=sc.nextDouble();
            z=x/y;
                
                if(z<0.01)
                {
                    **throw new MyclassEx("Number is too small");**
                }  
        }
        catch(MyclassEx e)
        {
            System.out.println("caught exception");
                
        }
        catch(ArithmeticException obj)
        {
            System.out.println("division not possible BY 0");
        }
        catch(InputMismatchException e2)
        {
            System.out.println("you have entered wrong key:");
        }
        finally
        {
            System.out.println("yoo");
        }
    }
}

D:\debolina\java\Error_handling>javac SimpleThrow.java

D:\debolina\java\Error_handling>java SimpleThrow       
Enter two numbers:45
0
yoo

Answer 1

If y is 0 then z is Double.POSITIVE_INFINITY or Double.NEGATIVE_INFINITY (depend on x sign). No Exception is thrown. In your example, z is Double.POSITIVE_INFINITY that it is greater than 0.01, so no MyClassEx exception is thrown.