温度计算代码Java

Question

I am trying to create a program that will print out the temperature in Fahrenheit. My goal is to not use any condition like the if statement or any loops.

public class TemperatureConverter {
    public static void main(String[] args) { 
        double celsius, fahrenheit; 
        Scanner input = new Scanner(System.in); 

        System.out.print("Enter the temperature in degrees Celsius:  "); 
        fahrenheit = input.nextDouble(); 
        celsius = 5.0/9.0 * (fahrenheit - 32); 

        System.out.printf(+celsius, "degrees Celsius is" +fahrenheit "degrees Fahrenheit"); 
    }
}

I am getting an error which is:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
The method printf(String, Object...) in the type PrintStream is not applicable for the arguments (double, String)
Syntax error on token ""degrees Fahrenheit"", delete this token

at TemperatureConverter.main(TemperatureConverter.java:14)

Edit:

I am not coming up with what I need to come up with. When I run this program the output is this:

For this example the user inputted 45 for the prompt of Celsius.

Enter the temperature in degrees Celsius: 45
42.77777777777778 degrees Celsius is 45.0 degrees Fahrenheit

Answer 1

Well just to fix your error:

System.out.print(celsius + "degrees Celsius is " + fahrenheit + " degrees Fahrenheit");

or you could do this if you want to use printf .

System.out.printf("%f degrees Celsius is %f degrees Fahrenheit",celsius,fahrenheit);

---

The reason I did all this is mainly just simple syntax. Strings are stuff within double quotes. "blah" for example is a String containing the word blah .

If you want to concatenate two strings then you use the + operator in Java. So you want to add "foo" and "bar" you write "foo" + "bar" and you get "foobar" .

In your attempt you have made two errors:

Firstly, (the intention of) string concatenation was done wrong. + celsius isn't a syntax error because celsius is a number but if it were a string then the compiler doesnt have anythign to the left of that + to concatenate the value of celsius with. "" + celsius would have been fine if you wanted to prepend nothing.

+ celsius effectively does nothing since it is a number. Positive or negative wont matter. -celsius of course flips the sign. If you want to display a positive number always (although your output would then be incorrect) you can use Math.abs(celsius).

Secondly, since you are using System.out.printf there is a specific format that you need to follow. ie the first argument must be a string (possibly with things like %d, %f, %s, etc) which the function will replace with the subsequent arguments that you provide it.

This is what my solution does, it uses %f (for floating point numbers) twice and I give it two things celsius and fahrenheit which are doubles and Java realizes that all is good and just replaces the values in there. You can use things like %.2f if you wanted two decimal places and such as well, this is the advantage of printf over a normal print or println (print + new line).

---

To fix the real other problem is that you are taking in temprature in celsius but saving it to the variable fahrenheit. If you just change that then all will be well.

System.out.print("Enter the temperature in degrees Fahrenheit:  "); 

Answer 2

To print output use:

System.out.println(celsius + "degrees Celsius is" + fahrenheit + "degrees Fahrenheit");

or

System.out.printf("%f degrees Celsius is %f degrees Fahrenheit",celsius,fahrenheit);

[EDIT] what went wrong.

java.lang.Error: Unresolved compilation problems: 
Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
The method printf(String, Object...)

• As the error says your syntax for printf() is wrong please refer link

Answer 3

尝试考虑以下打印声明：

 System.out.println(celsius+" is degrees Celsius and " +fahrenheit+ " is degrees Fahrenheit");

Answer 4

To start off, you are asking the user to enter the temperature in celcius and then assigning that value to a variable called fahrenheit. It doesn't seem to be very appropriate. As some other have said you aren't constructing the String correctly.

I have tidied up you code and changed the variable names as well as the formula to calculate the degrees in Fahrenheit.

    public static void main(String[] args) { 

        double celsius, fahrenheit; 
        Scanner input = new Scanner(System.in); 
        System.out.print("Enter the temperature in degrees Celsius:  "); 
        celsius = input.nextDouble(); 
        fahrenheit = celsius*9.0/5.0 + 32; 

        System.out.print(celsius + " degrees Celsius is " + fahrenheit+  " degrees Fahrenheit"); 
    }

Answer 5

    System.out.printf(+celsius, "degrees Celsius is" +fahrenheit "degrees Fahrenheit"); 

Check your original statement. You have missed adding one +(append) to add strings.

Use this 

   System.out.printf("%f degrees Celsius is %f degrees Fahrenheit",celsius,fahrenheit);