CODEWITHSUNDEEP
c++
bluetickk
bluetickk

Reputation: 689

Stack around the variable ' ' was corrupted

void GameBoard::enterShips()
{
    char location[1];
    int ships = 0;
    int count = 1;

    while(ships < NUM_SHIPS)
    {
        cout << "Enter a location for Ship " << count << ": ";
        cin >> location;
        cout << endl;

        Grid[location[0]][location[1]] = SHIP;
        ships++;
        count++;
    }
}

Im writing a battleship game. I have the board layouts working and the computers randomly generated ships. Now I am working on this method to prompt the user to enter coordinates for the ships When I run the program, it allows me to enter 5 ships. When I enter the 6th ship, it gives me this error.

Stack around the variable location was corrupted.

Ive looked for answers online and have not found anything exclusive.

Any help would be appreciated.

Upvotes: 8

Views: 74065

Answers (4)

Tugrul Ates
Tugrul Ates

Reputation: 9687

You are prompting the memory address of location array to your user. You should ask location indices separately:

void GameBoard::enterShips()
{
    int location[2];
    int ships = 0;
    int count = 1;

    while(ships < NUM_SHIPS)
    {
        cout << "Enter a location for Ship " << count << ": ";
        cin >> location[0];
        cin >> location[1];
        cout << endl;

        Grid[location[0]][location[1]] = SHIP;
        ships++;
        count++;
    }
}

Notice int location[2]; since an array of size 1 can only hold one element. I also changed the element type to int. Reading char's from the console will result in ASCII values, which are probably not what you want.

Upvotes: 7

James McNellis
James McNellis

Reputation: 355049

cin >> location;

location is an array of one char. This can't succeed because when you read from a stream into a char array, a null terminator has to be added (which takes one character). You will inevitably overrun the bounds of the array.

You can use a std::string, which will help you avoid any buffer overrun issues:

std::string location;
if (!(std::cin >> location)) {
    // handle input error
}

Note also that you probably need to convert the string representations of the numbers into numeric values. You can easily do this by reading from the stream into two int objects instead:

int x_location, y_location;
if (!(std::cin >> x_location >> y_location)) { 
    // Handle input error
}

if (x_location >= X_DIMENSION || x_location < 0 ||
    y_location >= Y_DIMENSION || y_location < 0) {
    // Handle out-of-range error 
}

// use x_location and y_location

Upvotes: 4

SoapBox
SoapBox

Reputation: 20609

You made the location variable only able to hold a single character. You access it expecting it to hold at least 2 characters. If you're using cin and expecting to read exactly two characters, a better method would be:

char locationX, locationY;
// ...
std::cin >> locationX >> locationY;
// ...
Grid[locationX][locationY] = SHIP;

Upvotes: 3

SLaks
SLaks

Reputation: 887453

location is an array of a single char.
There is no location[1].

Upvotes: 12

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