Write a method called fact that recursively calculates the factorial value of its single int parameter. The value returned by fact is a long ...

The program to this question can be given as follows:

Program:

//class

public class factorial / /defining class

{

//method fact

public static long fact (int x1) / /defining method fact

{

//conditional statement

if (x1 < = 1) / /if block checks parameter value less then equal to 1

{

return 1; / /return value

}

else / /else part

{

return (fact (x1 - 1) * (long) x1); / /return factors using recursive function

}

}

//method main

public static void main (String[] args) / /defining main method

{

long data=fact (5); //defining variable that holds function value

System. out. println ("Factorial is: "+data); / /print value

}

}

Output:

Factorial is: 120

Explanation:

In the above java program, a class is "factorial" is defined, inside the class, a static method "fact" is declared, that accepts an integer parameter that is "x1" and returns a long value, inside this method a conditional statement is used.

If the block it checks parameter value is less then equal to 1, if this condition is true, it will return 1 when this condition is not true. It will go in else part. In else part, it uses a recursive function to calculate factorial of a number and return its value. Then the main method is defined, inside this method a long variable "data" is defined, that call and holds fact function return value, and in the next line, the print function is used to print the data variable value.