Java 字符串输出为空白

下面的方法应该是可行的.

您可以使用System.out.print来请求同一行上的输入，也可以使用String.format来输出变量.别忘了关闭Scanner号公路！

Note:当获取部分字符串输入时，在请求更多字符串值之前，需要调用scanner.nextLine()来转储缓冲区.

import java.util.Scanner;

public class BasicInput {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Inputs
        int userInt;
        double userDouble;
        char myChar;
        String myString;

        System.out.print("Enter integer: ");
        userInt = scanner.nextInt();

        System.out.print("Enter double: ");
        userDouble = scanner.nextDouble();

        System.out.print("Enter character: ");
        myChar = scanner.next().charAt(0);

        scanner.nextLine(); // Clear the buffer

        System.out.print("Enter string: ");
        myString = scanner.nextLine();

        // 输出 the four values in order
        System.out.printf("%d %.2f %s %s%n", userInt, userDouble, myChar, myString);

        // 输出 the four values in reverse order
        System.out.printf("%s %s %.2f %d%n", myString, myChar, userDouble, userInt);

        // Cast the double to an integer, and output that integer
        System.out.println(userDouble + " cast to an integer is " + (int) userDouble);

        scanner.close();
    }
}

输出

Enter integer: 99
Enter double: 3.77
Enter character: z
Enter string: Howdy
99 3.77 z Howdy
Howdy z 3.77 99
3.77 cast to an integer is 3

如果要一次获取所有输入，可以执行以下操作:

import java.util.Scanner;

public class BasicInput {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Inputs
        int userInt;
        double userDouble;
        char myChar;
        String myString;

        System.out.print("Enter an integer, double, character, and a string: ");

        userInt = scanner.nextInt();
        userDouble = scanner.nextDouble();
        myChar = scanner.next(".").charAt(0); // See: https://stackoverflow.com/a/13942707/1762224
        myString = scanner.nextLine().trim();

        // 输出 the four values in order
        System.out.printf("%d %.2f %s %s%n", userInt, userDouble, myChar, myString);

        // 输出 the four values in reverse order
        System.out.printf("%s %s %.2f %d%n", myString, myChar, userDouble, userInt);

        // Cast the double to an integer, and output that integer
        System.out.println(userDouble + " cast to an integer is " + (int) userDouble);

        scanner.close();
    }
}

输出

Enter an integer, double, character, and a string: 99 3.77 z Howdy
99 3.77 z Howdy
Howdy z 3.77 99
3.77 cast to an integer is 3

如果您想严格控制可以输入的字符，可以使用以下模式:

myChar = scanner.next("[A-Za-z]").charAt(0); // Only alpha