Why am I getting a java.lang.NullPointerException:
Doctor[] doctor = new Doctor[MAXdoc];
String name, specialisation;
PrintWriter outputStream = null;
String fileName = "VetManagement.txt"; //This name can be read for the user to find the file.
try
{
outputStream =
new PrintWriter(
new FileOutputStream(fileName, true)); //This is the append from a old file.
}
catch (FileNotFoundException e)
{
System.out.println("Error: Saving data " + fileName);
System.exit(0);
}
System.out.print("What is the doctors name? ");
name = console.next();
String clearCode = console.nextLine();
for(int i =0; i < totalDoc; i++)
{
if(name.equalsIgnoreCase(doctor[i].getName()))
{
System.out.println("That name is already taken, please enter a new name: ");
name = console.next();
}
}
I have declared totalDoc = 0
, and it does not recognise this as it is an array it should work as it starts to count at 0. I have the same method for a pet array and it works. Why is this the case? What is a NullPointerException, and how do I fix it?
Initialize variables:
Scanner console = new Scanner(System.in);
int end;
int totalDoc = 0;
int totalPet = 0;
int MAXdoc = 4; //doctor array size. (max size)
int MAXpet = 5; //pet array size. (max size)
Doctor [] doctor = new Doctor[MAXdoc]; //Docter array
Pet [] pet = new Pet[MAXpet]; //pet arry
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