java - Do while 循环不会读取循环内输入的变量

Question

对于我的程序，我要编写一个接受 2 到 10 行之间的程序。生成 n 行的乘法三角形。每行包含不超过其行大小的条目。这一点我没有问题。然而，当用户在我的问题“请输入您想要打印的行数:”中输入数字 0 后，它应该终止循环并打印“感谢您使用此程序!”我使用了 DO...WHILE 循环来确定用户是否希望继续。在我的循环中，我将用户想要打印的数字声明为 int num。只要 num>=1，我的循环就应该继续。但是，我继续在 while (num>=1); 行收到错误消息说它找不到符号。为什么这么说呢？预先感谢您

import java.io.*;
import java.util.*;
public class Prog166g
{ //begin testshell 
public static void main (String[] args)
{ //begin main
 int i;
    int outer;
    int inner;
    int result;
    int example = 4;
    System.out.print("Number of rows for this triangle : " + example +"\n");
    for ( i = 1; i <= example; i++) {
        System.out.printf("%5s", i);
    }
    System.out.println("");
    for ( outer = 1; outer <= 4; outer++) {
        for ( inner = 1; inner <= outer; inner++) {
            result = outer * inner;
            System.out.printf("%5s", result);
        }
        System.out.println("");
    }
    System.out.println("");

        do{
        System.out.print("Please enter the number of rows you would like to print: ");
        Scanner kbReader = new Scanner(System.in);
        int num = kbReader.nextInt();
        System.out.println("");
        System.out.println("Number of rows for this triangle: " + num);
        for ( i = 1; i <= num; i++) {
            System.out.printf("%5s", i);
        }
        System.out.println("");
        for ( outer = 1; outer <= num; outer++) {
            for ( inner = 1; inner <= outer; inner++) {
                result = outer * inner;
                System.out.printf("%5s", result);
            }
        }
     }while (num>=1);


   System.out.println("Thank you for using this program"); 
}// ends main
}//ends testshell

Answer 1

“num”的声明必须位于“do”之前。这可能是:

...
int num;
do {
    ...
    num = kbReader.nextInt();
    ...;
}
...