java - 结果没有初始化？

Question

import java.util.*;

//Creates a program which allows the user to find the factorial of a number

public class forLoop {
    public static void main (String [] args) {

        Scanner input = new Scanner(System.in);

        System.out.println("Enter the number you want the factorial from: ");
        int number = input.nextInt(); // user input
        input.close();

        int result_2 = getFactorial(number); //initializes getFactorial method
        System.out.println("The factorial of " + number + " is " + result); //prints results

        }

    public static int getFactorial (int num1) {
        int result;

        for (int times = num1; times <= 1; times--) { //repeats loop until times <=1

            result = num1 * (num1 - 1); //does the factorial equation

        }

        return result;  // returns results (here is the problem)
    }
}

Answer 1

编译器不能假定循环至少执行一次——这是 result 的必要条件得到分配。

更改声明result解决问题的方法如下:

int result = 1;

这将有助于您的代码编译，但它不会修复计算阶乘时的逻辑错误:目前，由于错误的循环条件，您的循环将无限期地运行。

您应该将 1 中的数字相乘至 num1 ， 包括的。改变循环条件 times >= 1而不是 times <= 1 , 和循环体到 result *= times修复此错误。