我应该在阶乘计算器代码中添加或删除什么

Question

我是编码新手，所以我一直对应该在代码中添加或删除什么感到困惑。当我输入2的阶乘时，它也打印出阶乘1，而我只想打印出2的阶积。

import java.util.Scanner;
public class FactorialCalculator {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);

int i, fact = 1, number;

System.out.println("<------ Factorial Calculator ------>");
System.out.print("Enter a positive integer: ");
number = input.nextInt();

if (number <= 2) {
for (i = 1; i<=number; i++) {
fact = fact * i;
System.out.println("2! = 1 x 2 ");
System.out.println("The Factorial of 2 is: "+fact);             
}
}       
}
}

输出：

<------ Factorial Calculator ------>
Enter a positive integer: 2
The Factorial of 2 is: 1
The Factorial of 2 is: 2

Answer 1

将打印语句移出循环。

if (number <= 2) {
for (i = 1; i<=number; i++) {
fact = fact * i;
}
System.out.println("The Factorial of 2 is: "+fact);             
}

但您可能希望允许比2更大的值。不要忘记0!和1!都等于1。

这样试试吧。

int fact = 1; //starting point for all factorials.
if (number >= 2) {
for (int i = 2; i <= number; i++) {
fact = fact * i;
}
}
System.out.println(number + "! = " + fact);

我认为你混淆了<= 2和>= 2。CCD_ 7将仅允许值CCD_。您想要的是允许值>= 2或2, 3, 4, ...