java - 如何将 if/else if 代码中的整数转入该代码外部的整数？ (java)

Question

我正在尝试编写一个可以解决指数问题的代码，并且可以解决整数输入和单词输入(即一、二...等)的指数问题。我几乎已经弄清楚了整数部分，但是我被困在“单词输入”部分。主要是，我的代码中单词部分的最后部分(int base = y，exponent = z)，其中我可以计算指数不起作用，因为无法从 if/else if 语句中提取 y 和 z

我如何编写代码，以便 int base = y, exponent = z 可以从各自的 if/else if 代码中提取？

非常感谢!

public static void main(String[] args) {
    Scanner choice = new Scanner(System.in);
    System.out.println("Enter 1 for Alphabetical Input, 2 for numerical input:");
    int solution = choice.nextInt();

    if(solution == 1) {
        for(int i=1; i<=100;i++) {
            Scanner words = new Scanner(System.in);

            System.out.print("Enter your base");
            String x = words.toString();
            String x1 = "zero";
            String x2 = "one";
            String x3 = "two";
            String x4 = "three";
            String x5 = "four";
            String x6 = "five";
            String x7 = "six";
            String x8 = "seven";
            String x9 = "eight";
            String x10 = "nine";
            String x11 = "ten";

            if(x == x1) {
                int y = 0;
            }
            else if(x == x2) {
                int y = 1;
            }
            else if(x == x3) {
                int y = 2;
            }
            else if(x == x4) {
                int y = 3;
            }
            else if (x == x5) {
                int y = 4;
            }
            else if (x == x6) {
                int y = 5;
            }
            else if (x == x7) {
                int y = 6;
            }
            else if (x == x8) {
                int y = 7;
            }
            else if (x == x9) {
                int y = 8;
            }
            else if (x == x10) {
                int y = 9;
            }
            else if (x == x11) {
                int y = 10;
            }
            else {
                System.out.println("I can't read that!");
            }
            System.out.println("Enter your exponent");

            Scanner exponent = new Scanner(System.in);

            String a = exponent.toString();


            if(a == x1) {
                int z = 0;
            }
            else if(a == x2) {
                int z = 1;
            }
            else if(a == x3) {
                int z = 2;
            }
            else if(a == x4) {
                int z = 3;
            }
            else if (a == x5) {
                int z = 4;
            }
            else if (a == x6) {
                int z = 5;
            }
            else if (a == x7) {
                int z = 6;
            }
            else if (a == x8) {
                int z = 7;
            }
            else if (a == x9) {
                int z = 8;
            }
            else if (a == x10) {
                int z = 9;
            }
            else if (a == x11) {
                int z = 10;
            }
            else {
                System.out.println("I can't read that!");
            }
            int base = y, exponents = z; //this does not work, y and z aren't pulled 
            double result = Math.pow(base, exponents);
            }

    }
    else if(solution ==2 ) {
        for(int i=1;i<=100;i++){
            Scanner number = new Scanner(System.in);

            System.out.print("Enter your base:");

            int x = number.nextInt();

            Scanner up = new Scanner(System.in);

            System.out.print("Enter your exponent:");

            int y = up.nextInt();

            int base = x, exponent = y;
            double result = Math.pow(base, exponent);

            System.out.println("Answer = " + result);
        }
    }
    else {
        System.out.println("Could not read input");
    }
}

}

Answer 1

将它们声明为 @Shuang Li在 for 循环前面说，否则 y 和 z 仅在相关 if 中可见。

除此之外，您不应该使用 if (x == x1)因为这会检查您的输入是否等于 String x1 的内存地址，因此会打印出“我无法读取!”。要检查字符串是否相等，您需要使用 if (x.equals(x1)) .

使用String x = words.toString();进一步阅读用户的输入没有做您希望它做的事情，因为它立即跳到 if 部分传递 null至String x 。相反，你应该使用

String x = words.next();或String x = words.nextLine();

与 .toString(); 不同方法.next();和.nextLine();是 Scanner 的方法因此他们将等待任何输入，只有在获得输入后，代码才会被进一步执行。

所以这将是您的目标:

public static void main(String[] args) {
    Scanner choice = new Scanner(System.in);
    System.out.println("Enter 1 for Alphabetical Input, 2 for numerical input:");
    int solution = choice.nextInt();

    int y = 0;
    int z = 0;

    if (solution == 1) {
        for (int i = 1; i <= 100; i++) {
            Scanner words = new Scanner(System.in);

            System.out.print("Enter your base");
            String x = words.next();
            String x1 = "zero";
            String x2 = "one";
            String x3 = "two";
            String x4 = "three";
            String x5 = "four";
            String x6 = "five";
            String x7 = "six";
            String x8 = "seven";
            String x9 = "eight";
            String x10 = "nine";
            String x11 = "ten";

            if (x.equals(x1)) {
                y = 0;
            } else if (x.equals(x2)) {
                y = 1;
            } else if (x.equals(x3)) {
                y = 2;
            } else if (x.equals(x4)) {
                y = 3;
            } else if (x.equals(x5)) {
                y = 4;
            } else if (x.equals(x6)) {
                y = 5;
            } else if (x.equals(x7)) {
                y = 6;
            } else if (x.equals(x8)) {
                y = 7;
            } else if (x.equals(x9)) {
                y = 8;
            } else if (x.equals(x10)) {
                y = 9;
            } else if (x.equals(x11)) {
                y = 10;
            } else {
                System.out.println("I can't read that!");
            }
            System.out.println("Enter your exponent");

            Scanner exponent = new Scanner(System.in);

            String a = exponent.next();

            if (a.equals(x1)) {
                z = 0;
            } else if (a.equals(x2)) {
                z = 1;
            } else if (a.equals(x3)) {
                z = 2;
            } else if (a.equals(x4)) {
                z = 3;
            } else if (a.equals(x5)) {
                z = 4;
            } else if (a.equals(x6)) {
                z = 5;
            } else if (a.equals(x7)) {
                z = 6;
            } else if (a.equals(x8)) {
                z = 7;
            } else if (a.equals(x9)) {
                z = 8;
            } else if (a.equals(x10)) {
                z = 9;
            } else if (a.equals(x11)) {
                z = 10;
            } else {
                System.out.println("I can't read that!");
            }
            int base = y, exponents = z; // this does not work, y and z aren't pulled
            double result = Math.pow(base, exponents);
            System.out.println("Answer = " + result);
        }

    } else if (solution == 2) {
        for (int i = 1; i <= 100; i++) {
            Scanner number = new Scanner(System.in);

            System.out.print("Enter your base:");

            int x = number.nextInt();

            Scanner up = new Scanner(System.in);

            System.out.print("Enter your exponent:");

            y = up.nextInt();

            int base = x, exponent = y;
            double result = Math.pow(base, exponent);

            System.out.println("Answer = " + result);
        }
    } else {
        System.out.println("Could not read input");
    }
}