Error : Index was outside the bounds of the array. [duplicate]

Answer 1

public int[] posStatus;       

public UsersInput()    
{    
    //It means postStatus will contain 9 elements from index 0 to 8. 
    this.posStatus = new int[9];   
}

int intUsersInput = 0;   

if (posStatus[intUsersInput-1] == 0) //if i input 9, it should go to 8?    
{    
    posStatus[intUsersInput-1] += 1; //set it to 1    
} 

Answer 2

//if i input 9 it should go to 8?

You still have to work with the elements of the array. You will count 8 elements when looping through the array, but they are still going to be array(0) - array(7).

Answer 3

You have declared an array that can store 8 elements not 9.

this.posStatus = new int[8]; 

It means postStatus will contain 8 elements from index 0 to 7.