java - Java中的基本输入和输出

Question

我正在使用 NetBeans IDE 7.4，我对 Java 很陌生，我试图让用户输入两个数字（它们都是双精度数），然后将它们存储在另一个变量中。我去过几十个教程网站，但它们都不好。如何获得基本的输入和输出？

Answer 1

原始示例：

import java.util.Scanner;

public class TestIO {

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

        System.out.println("Print something:");    // printing output
        String text = scanner.nextLine();          // taking input

        System.out.println("You have printed the following text: " + text);
    }

}

更新：
对不起，错过了你想要双打的重点。干得好：

import java.util.Scanner;
import java.util.InputMismatchException;

public class TestIO {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double firstDouble = 0L;
        double secondDouble = 0L;
        while (true) {  // take input (two doubles) until successful
            System.out.println("Print two doubles (press enter after each input):");
            try {
                firstDouble = scanner.nextDouble();
                secondDouble = scanner.nextDouble();
            } catch (InputMismatchException e) {
                System.out.println("Wrong input. You must print doubles.\n" +
                                   "Depending on your locale, as a decimal separator " +
                                   "use either a comma or a dot.\n");
                scanner.nextLine(); // clearing the buffer with the wrong input
                                    // to avoid infinite loop
                continue;
            }
            break; 
        }
        // Printing the user input (limiting doubles to 3 decimal places)
        System.out.format("You have printed %.3f and %.3f %n", 
                          firstDouble, secondDouble);
    }
}

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推荐阅读：

• 官方Oracle Java 教程- 内容丰富且易于理解
• 课程：基本 I/O（来自上述教程）

Answer 2

import java.util.*;

public class Test
{
static Scanner console = new Scanner (System.in)
public static void main (String[] args)
{
double input1, input2; // Declares the double value of input1 and input2
input1 = console.nextDouble(); // User inputs value into input1
input2 = console.nextDouble();

String value1 = "" + input1; // Storing value into a String
String value2 = "" + input2;
// If you want to store it in let's say string.
// Or else i think / int value1 = Integer.parseInt(input1);
// This changes the double value into an Int value
// Something like that.
}
}

不太确定这是否是您的问题，因为输出值也可能与

System.out.println(input1); // This outputs the value of input1 on the screen.