在这里，我们将编写程序，使用递归找出数字的阶乘。
程序 1：
程序将提示用户输入数字。一旦用户提供输入，程序将计算所提供输入数的阶乘。
/** * @author: BeginnersBook.com * @description: User would enter the 10 elements * and the program will store them into an array and * will display the sum of them. */import java.util.Scanner;class FactorialDemo{ public static void main(String args[]){ //Scanner object for capturing the user input Scanner scanner = new Scanner(System.in); System.out.println("Enter the number:"); //Stored the entered value in variable int num = scanner.nextInt(); //Called the user defined function fact int factorial = fact(num); System.out.println("Factorial of entered number is: "+factorial); } static int fact(int n) { int output; if(n==1){ return 1; } //Recursion: Function calling itself!! output = fact(n-1)* n; return output; }}
输出：
Enter the number:5Factorial of entered number is: 120
程序 2：
如果您不想要用户干预并且只想在程序中指定数字，请参考此示例。
class FactorialDemo2{ public static void main(String args[]){ int factorial = fact(4); System.out.println("Factorial of 4 is: "+factorial); } static int fact(int n) { int output; if(n==1){ return 1; } //Recursion: Function calling itself!! output = fact(n-1)* n; return output; }}输出：
Factorial of 4 is: 24
