java - 使用 3 个函数将温度从摄氏度转换为华氏度

Question

我是java新手，我正在尝试编写一个将摄氏度转换为华氏度的程序

import java.util.Scanner;

public class Temps
{

   public static void main(String[] args) 
   {

      System.out.print("Enter temp(70 f or 20 c): ");
      double  temp = keyboard.nextDouble();
      String units = keyboard.next();
      if (units.equal("f"))
         newtemp =  ftoc(temp);
      else if (units.equals("c"))
         newtemp = ctof(temp);
      else System.err.println("units must be c or f");
   }

          public static double ftoc (int c)
          return (( 5.0 / 9.0) * (c - 32));
       }

       public static double ctof (int f)
       {
          return ((9.0/5.0)* f+32);
       }
    }

有人可以向我解释一下我做错了什么吗

Answer 1

问题不少

查看固定代码中的注释

    Scanner keyboard = new Scanner(System.in);
    System.out.print("Enter temp(70 f or 20 c): ");
      double  temp = keyboard.nextDouble();
      String units = keyboard.next();
      double newtemp = -1;   // not declared
      if (units.equals("f"))  // should be equals
         newtemp =  ftoc(temp);
      else if (units.equals("c"))
         newtemp = ctof(temp);
      else System.err.println("units must be c or f");

      System.out.println("the new temp is " + newtemp);  // need to print it out
   }

      public static double ftoc (double c) {   // take a double
          return (( 5.0 / 9.0) * (c - 32));
       }

       public static double ctof (double f)  // take a double
       {
          return ((9.0/5.0)* f+32);
       }