Error : Index was outside the bounds of the array.

I'm aware of what the issue is stating but I am confused to how my program is outputting a value that's outside of the array.. I have an array of ints which is 0 - 8 which means it can hold 9 ints, correct? I have an int which is checked to make sure the users input value is 1-9. I remove one from the integer (like so) ``` if (posStatus[intUsersInput-1] == 0) //if pos is empty { posStatus[intUsersInput-1] += 1; }//set it to 1 ``` then I input 9 myself and I get the error. It should access the last int in the array, so I don't see why I'm getting an error. Relevant code: ``` public int[] posStatus; public UsersInput() { this.posStatus = new int[8]; } int intUsersInput = 0; //this gets try parsed + validated that it's 1-9 if (posStatus[intUsersInput-1] == 0) //if i input 9 it should go to 8? { posStatus[intUsersInput-1] += 1; //set it to 1 } ``` Error: ``` "Index was outside the bounds of the array." "Index was outside the bounds of the array." ```