编程Java求任意一个正整数的阶乘

1、输入一个正整数，并求出它的阶乘

While循环

import java.util.Scanner;

public class NumberLayer {

/**

* @param args

*/

public static void main(String[] args) {

System.out.print("请输入一个正整数:");

Scanner ScNumber=new Scanner(System.in);

int num=ScNumber.nextInt();

System.out.println();

int layer=num;

int i=1;

//标签,用来标记下一次符合要求的循环从这个标签开始

loop:while(true){

layer=layer*(num-i);

i++;

if(i==num)

break loop;

}

System.out.println(num+"的阶乘为:"+layer);

}

}

2、for循环

import java.util.Scanner;

public class NumberLayer {

/**

* @param args

*/

public static void main(String[] args) {

System.out.print("请输入一个正整数:");

Scanner ScNumber=new Scanner(System.in);

int num=ScNumber.nextInt();

System.out.println();

int layer = num;

for(int i=1;i

layer=layer*(num-i);

}

System.out.println(num+"的阶乘为:"+layer);

}

}