Java error, duplicate local variable

Question

I'm trying to debug a portion of code for an assignment (I'm still very new to Java) and have combed through many resources to solve this conflict but still can't quite work it out.

public static void main(String [] args){
    Scanner keyboard = new Scanner(System.in);
    String input = null;
    do
    {
      System.out.println("Enter 'A' for option A or 'B' for option B.");
      String input = keyboard.next();
      input.toLowerCase();
      input.charAt(0);  
    }
    while ((input != "a") || (input != "b"));
}

I always get a Duplicate Local Variable error with the input String.

Any help would be greatly appreciated!

Answer 1

replace

String input = keyboard.next();

with

input = keyboard.next();

If you put a String before the variable name it is a declaration. And you can declare a variable name only once in a scope.