两个for循环，下一个for的变量不能是上一个for的变量？

Question

不太懂为什么？

import java.util.Scanner;

public class B1022 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int A = in.nextInt();
        int B = in.nextInt();
        int P = in.nextInt();
        int C = A + B;
        int []numD = new int[100];


        while(C != 0)
        {
            for (int i = 0; i < 100; i++)
            {
                numD[i++] = C % P;
                C = C / P;              
            }           
        }
         /*如何把未知长度的数组倒着输出*/
        for (int x = i - 1; x >= 0; x--)   /*error: i cannot be a variable*/
        {
            System.out.print(numD[x]);
        }       
        in.close();
    }

}

Answer 1

括号{}标记了变量i的作用域，超出作用域之后就不能被解析器识别。

import java.util.Scanner;

public class B1022 {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int A = in.nextInt();
int B = in.nextInt();
int P = in.nextInt();
int C = A + B;
int []numD = new int[100];

    while(C != 0)
    {
        for (int i = 0; i < 100; i++)
        {
            numD[i++] = C % P;
            C = C / P;              
        }           
    }
     /*如何把未知长度的数组倒着输出*/
    for (int x = 100 - 1; x >= 0; x--)   /*error: i cannot be a variable*/
    {
        System.out.print(numD[x]);
    }       
    in.close();
}