为什么我的 while 循环总是出现“非法类型开始”？答案

【问题标题】：Why do I keep getting 'illegal start of type' for my while loop?为什么我的 while 循环总是出现“非法类型开始”？
【发布时间】：2022-06-11 00:12:56
【问题描述】：

此时，我的所有数学运算都正确，但我无法弄清楚为什么下面编写的代码不断出现此错误：

Objective9Lab6.java:8: error: illegal start of type
    while (keepGoing) {
    ^
Objective9Lab6.java:8: error: <identifier> expected
    while (keepGoing) {
                    ^

import java.util.Scanner;

public class Objective9Lab6 {

public static void main(String[] args) {
    printMenu();}

    while (keepGoing) {
        System.out.print("Which would you like to do? ");
        choice = kb.nextInt();
        double average = (num1 + num2) / 2;
        double sum = num1 + num2;
        double calcTax = sum * (8.31/100);
        Scanner kb = new Scanner(System.in);
        double num1, num2;
        boolean keepGoing = true;
        int choice;
        double answer = 0.0;

        System.out.print("Please give me a number: ");
        num1 = kb.nextDouble();
        System.out.print("Please give me another number: ");
        num2 = kb.nextDouble();

        switch (choice) {
            case 1:
                System.out.println(+num1 + " + " + num2 + " = " + sum + ".");
                break;
            case 2:
                System.out.println("The average of " + num1 + "and" + num2 + "is" + average + ".");
                break;
            case 3:
                System.out.println("The amount in tax to be collected from a purchace of " + num1 + " and " + num2 + " is " + calcTax + ".");
                break;
            case 4:
                System.out.println("You've chosen to quit.");
                return;
            default:
                System.out.println("Invalid entry. Please try again.");
      }
    }
        public static void printMenu() {
                    System.out.println();
                    System.out.println("========= MENU =========");
                    System.out.println("|                      |");
                    System.out.println("|   1. Add Numbers     |");
                    System.out.println("|   2. Find Average    |");
                    System.out.println("|   3. Calculate Tax   |");
                    System.out.println("|   4. Exit            |");
                    System.out.println("|                      |");
                    System.out.println("========================");
                    System.out.println();
  }
}

我觉得这与我声明布尔值的位置有关，但是在我移动该行的任何地方我都会收到相同的错误。

【问题讨论】：

错字。从printMenu();} 中删除}
在while循环之前声明keepGoing或使用while (true)
错字问题被认为质量低下。

标签： java while-loop boolean