对不起我的初学者错误，但我正在编写一个计算器，它将华氏温度转换为摄氏度，将摄氏度转换为华氏温度，但我一直收到这个错误：
Exception in thread "main" java.lang.NumberFormatException:
For input string: "69C"
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1241)
at java.lang.Double.valueOf(Double.java:504)
at Converter.main(Converter.java:39)
这是我的代码，希望对你有所帮助：
import java.util.Scanner;
public class Converter {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.println("Welcome to the Fahrenheit/Celsius Converter!");
System.out.println("To convert, type in your temperature and the
identify if you are using fahrenheit or celsius.");
System.out.println("Example: 69F or 69C F = Fahrenheit C = Celsius");
String temperature;
char f = 'f';
char c = 'c';
double answer , temp;
temperature = keyboard.nextLine();
if (temperature.contains("F")) {
temperature = temperature.replace(f , ' ');
temp = Double.valueOf(temperature);
answer = temp - 30 / 2;
System.out.println("Poof! The temperature is " + answer + "C");
} else {
System.out.println("You entered the temperature wrong!");
}
if (temperature.contains("F")) {
temperature = temperature.replace(f , ' ');
temp = Double.valueOf(temperature);
answer = temp - 30 / 2;
System.out.println("Poof! The temperature is " + answer + "C");
} else {
System.out.println("You entered the temperature wrong!");
}
if (temperature.contains("C")) {
temperature = temperature.replace(c , ' ');
temp = Double.valueOf(temperature);
answer = temp + 30 * 2;
System.out.println("Poof! The temperature is " + answer + "F");
} else {
System.out.println("You entered the temperature wrong!");
}
if (temperature.contains("c")) {
temperature = temperature.replace(c , ' ');
temp = Double.valueOf(temperature);
answer = temp + 30 * 2;
System.out.println("Poof! The temperature is " + answer + "F");
} else {
System.out.println("You entered the temperature wrong!");
}
}
}