Factorial of n is the product of all positive descending integers. Factorial of n is denoted by n!. For example:
4! = 4*3*2*1 = 24 5! = 5*4*3*2*1 = 120
Factorial Program using while loop
public class FactorialProgram {
public static void main(String[] args) {
int factNumber = 4;
int total = 1;
int n = 1;
while (n <= factNumber) {
total = total * n;
n = n + 1;
}
System.out.println("Factorial of " + factNumber + " is " + total);
}
}
Output
Factorial of 4 is 24
Factorial Program using For loop
public class FactorialProgram {
public static void main(String[] args) {
int factNumber = 5;
int total = 1;
for (int n = 1; n <= factNumber; n++) {
total = total * n;
}
System.out.println("Factorial of " + factNumber + " is " + total);
}
}
Output
Factorial of 5 is 120
Factorial Program using recursion
class FactorialProgram {
public static int factorial(int n) {
if (n == 0) {
return 1;
} else {
return (n * factorial(n - 1));
}
}
public static void main(String args[]) {
int total = 1;
int factNumber = 5;
total = factorial(factNumber);
System.out.println("Factorial of " + factNumber + " is " + total);
}
}
Output
Factorial of 5 is 120
