在Java中，如何让变量分别打印两个double，而不是将它们相加？

Question

我必须创建一个方法（outputDegreesF），它打印下面的信息（温度转换），并且只接受一个参数。如何让变量degreesC分别打印degreesC和fahrenheit，而不只是添加它们？比如“0.032.0”。我无法将任何内容更改为字符串或Java

public class tempChart {

        public static void degreeHeader (String cTitle, String fTitle) {
      System.out.println(cTitle + fTitle);
      }

        public static void outputDegreesF (double degreesC) {
         double fahrenheit = 32.0 + (degreesC * 9.0 / 5.0);
         degreesC = degreesC + fahrenheit;
         System.out.print(degreesC);
        }

      public static void main(String[] args) {
       degreeHeader("Degrees (C)", " Degrees (F)\n");
       System.out.println();
       outputDegreesF(0.0);
       outputDegreesF(5.0);
       outputDegreesF(10.0);
       outputDegreesF(15.0);
       outputDegreesF(20.0);
       outputDegreesF(25.0);
       outputDegreesF(30.0);
       outputDegreesF(35.0);
     }



    }

Answer 1

您只需要将数字打印为字符串。 将outputDegreesF()替换为

public static void outputDegreesF(double degreesC) {
    double fahrenheit = 32.0 + (degreesC * 9.0 / 5.0);

    System.out.print(degreesC + " " + fahrenheit); // Easier
    // Or
    System.out.printf("%.7f %.7f", degreesC, fahrenheit); // Used more and lets you format
}

如果要更改printf打印的小数位数，请将7更改为所需的数量

附言： 您不需要System.out.println();行，因为在前一行中已经添加了新行（字符串中的\n）

Answer 2

我假设您可以创建一个嵌套的Degrees类，并让该类为您执行从摄氏到华氏（或从华氏到摄氏）的转换。下面是一个可运行的示例，用于将摄氏度值数组转换为华氏度：

package tempchart;

public class TempChart {

    public static void main(String[] args) {
        // The temperatures in Celsius you want to convert
        // to Fahrenheit and table within a 1D double type 
        // array.
        double[] degreesCelsius = 
                {0.0, 5.0, 10.0, 15.0, 20.0, 25.0, 30.0, 35.0};

        // Declare the Degrees class.
        Degrees deg = new Degrees();
        // Table Header
        System.out.printf("%s | %8s%n", "Celcius", "Fahrenheit");
        System.out.println("========+===========");

        // Generate the table based on the temperatures 
        // held within the degreesCelsius array...
        for (int i = 0; i < degreesCelsius.length; i++) {
            deg.setCelsius(degreesCelsius[i]);
            System.out.printf("%-7.2f | %5.2f%n", deg.celsius, deg.fahrenheit);
        }
    }

    // Static Nested Class - Degrees
    static class Degrees {
        public double celsius;
        public double fahrenheit;

        // Getters And Setters
        public double getCelsius() {
            return celsius;
        }

        public void setCelsius(double celsius) {
            this.celsius = celsius;
            //Convert to Fahrenheit - Multiply by 9, then divide by 5, then add 32
            this.fahrenheit = (((celsius * 9) / 5) + 32);
        }

        public double getFahrenheit() {
            return fahrenheit;
        }

        public void setFahrenheit(double fahrenheit) {
            this.fahrenheit = fahrenheit;
            //Convert to Celcius - Deduct 32, then multiply by 5, then divide by 9
            this.celsius = (((fahrenheit - 32.0) * 5) / 9);
        }
    }
}

也可以将其他温度标度应用于上述嵌套类