Please Who knows how to Write a program in java to call a method for calculating the factorial of any number

Answer 1

An example for small numbers:

int num = 5;
int factorial = 1;

for(int i = num; i > 0; i--){

factorial*=i;
}

System.out.println(factorial);

public static int factorial (int num){
//calculate factorial
return factorial;
}

main:
System.out.println (factorial (num));

Answer 2

In the challange https://www.sololearn.com/learn/6639/?ref=app
are some solutions. But the fractional grows very fast, so you have the problem to choose the datatype. Biginteger could be the right choice .
Good luck...