Question

import java.util.*;

class Sept1Little {
    public static void main (String args []) {

        Scanner s = new Scanner(System.in);

        System.out.println("Hey! I'm not gonna program today o.o but I'm gonna do a little program :3");
        System.out.println("Let's play with some math!");
        System.out.println("Enter two numbers and magic will happen");
        System.out.print("Enter the first number: ");
        float a = s.nextInt();
        System.out.print("Enter the second number: ");
        float b = s.nextFloat();
        float c = (float) Math.pow( a, b);
        System.out.printf("The number is :%f\n" , c);
        System.out.println("We love Bernie Sanders!");
        System.out.println("Come on, let's push him over the line!");
        int poll1 = 30;
        System.out.println("Current poll amount: " + poll1);
        System.out.println("Let's add 7% and an extra 1%!");
        int poll2 = poll1 + 7;
        int poll3 = ++poll2;
        System.out.println("Bernie Sanders would get :" + poll3 + ". Bernie would get a better percentage than Hillo Clinto-Money");
        System.out.println("Write in the best US President Nominee: ");
        String president = Keyboard.readString();
        if (president.equals("Bernie Sanders")){
            System.out.println("You chose Bernie Sanders.");

        }
        else if (president.equals("Donald Trump")) {
            System.out.println("You chose Donald Trump");

        }
        else if (president.equals("Hillary Clinton")) {
            System.out.println("You chose Hillary Clinton ");

        }
        else {
            System.out.println("Choose someone we know...");

        }
        System.out.println("Let's calculate how much money you owe the govt by... SQUARE ROOTING IT!");
        System.out.print("Enter the amount of money you owe the govt: ");
        float debt1 = Keyboard.readFloat();
        System.out.printf("The amount is now :%f\n" , Math.sqrt(debt1));
        System.out.println("Welcome to the Euro to Dollar Convertor!");
        System.out.print("Enter the amount in US Dollars you wish to convert to Euro: ");
        float euro1 = Keyboard.readFloat();
        final float rate = (float) 1.13;
        System.out.printf("The amount in Euro is %f\n" , euro1 / rate);
    }
}

正如您所看到的，当我要求被提名者时，我正在使用Keyboard.readString();。当我使用s.readLine();时，它不起作用，它会跳到else子句然后崩溃，因为之后需要总统输入float值。对不起，这有点政治，但我没有打扰它。当我将"Bernie Sanders"作为"BernieSanders"时，我没有收到错误，有人知道为什么吗？

Answer 1

我想这是因为s.nextFloat();和s.nextInt();分别只读取float和int，而不是整行，因此{{1}的光标它位于float或int之后，而不是在下一行。这是一个例子：

如果您的输入是：

Scanner

你的代码中有：

5 Bench
Prove

为什么它没有捕获a= s.nextInt(); //5 b= s.nextLine(); //" Bench"值？因为使用Prove之后s.nextInt()的光标在Scanner之后，而不是在下一行（我们拥有5的行）之后。为了避免这种情况，你必须阅读该行的其余部分（因为你不想要它而对你没用）但没有得到这个值。像这样：

Prove

P.S。：每次使用a= s.nextInt(); //5 s.nextLine(); //We go to the next line b= s.nextLine(); //"Prove"或s.nextLine();作为上面的示例时，您必须使用s.nextInt();。

我希望它会对你有所帮助！

在比较字符串时，在Java中使用if with Scanner并不能正常工作

1 个答案: