Question

Java generics

Write a program that calls a method to multiply two integers and return the integer result. Modify the program to make the method generic, calling it with two generic data types and then returning the result in the same type which also has to be generic. Call the method two times, once with an integer and once with a double in your main program and display the results

Answer 1

//Java code

public class Multiply {
    public static void main(String[] args)
    {
        int z = getMultiply(5,6);
        System.out.println("The result: "+z);
    }
    public static int getMultiply(int x , int y)
    {
        return x*y;
    }
}

//Output

//Generic version

//Java code

public class Multiply<T> {
    public static void main(String[] args)
    {
        int z = getMultiply(5,6);
        System.out.println("The result: "+z);
        // for double
       double z1=  getMultiply(55.6, 67.8);
       System.out.println("The result: "+z1);
    }
    @SuppressWarnings("unchecked")
    public static  <T extends Number> T getMultiply(T x ,  T y)
    {
        T t;
        if (x instanceof Integer && y instanceof Integer)
          return (T) (Integer)(x.intValue()*y.intValue());
        else
            return (T) (Double)(x.doubleValue()*y.doubleValue());
    }
}

//Output

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