View difference between Paste ID: K1PJA6Dt and X3048uA2

 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 = 0, c;
+		char f = 'f';
 		double answer , temp;
 
 		temp = keyboard.nextDouble();
 
 		if (temperature.contains("F")) {
 			String StringVariable = null;
-			StringVariable.replace(f , ' ');
+			StringVariable.replace(f , '');
 			answer = temp - 30 / 2;
 			System.out.println("Poof! The temperature is " + answer + "C");
 		} else {
 			System.out.println("You entered the temperature wrong!");
 
 
 			}
 	}
 
 }