Updating a 2d integer array in a struct with a pointer

Question

I'm trying to implement a coordinate system for a player in a game.

I have a struct

typedef struct player {
    int playerPosition[1][5];
}

I create a pointer to that struct

struct* player playerPtr;
struct player playerOne;
playerPtr = &playerOne;

If during the game, I want to update the coordinate of the player to position [1,2].

I get errors when I use playerPtr->playerPosition=[1][2] ;

What's the correct way of doing this?

Answer 1

As written, you could do this:

playerPtr->playerPosition[0][2] = 100;

But probably you have an error here:

int playerPosition[1][5];

Because it rarely makes sense to have an array of size 1. Did you really mean for playerPosition to be a 1x5 array of ints? It looks like you wanted something like this:

struct position {
    int x, y;
};

struct player {
    position playerPosition;
};

Then you would do this:

playerPtr->playerPosition.x = 1;
playerPtr->playerPosition.y = 2;

Answer 2

playerPtr->playerPosition=[1][2]; will give you error (syntactically wrong)

you are not specifying the array index at which the data is to be stored, also you cant store data by that way in C .

correct way would be:

playerPtr->playerPosition[0][0] = 1;
playerPtr->playerPosition[0][1] = 2;
.
.
.
playerPtr->playerPosition[9][0] = 19;
playerPtr->playerPosition[9][1] = 20;

which is valid if you declare your array like this:

int playerPosition[10][2];

which will allow you to store ten coordinates.

2Dimentional arrays such as array[1][10] are same as array[10] (for usage, I am not certain about memory allocation, 2D array might require more memory)

I think you could use different but easier approach to this problem:

typedef struct position{
    int x, y;
    float refpos; //position from some reference point (like healing circle)
}position;

typedef struct player{
    char name[20];
    int health, attack, defense; //can be float too
    position coord[20];
}player;

player player1, *playerPtr;
playerPtr = &player1;
playerPtr->position[0].x = 3;
playerPtr->position[0].y = 4;
playerPtr->position[0].refpos = 5; //Pythagorean triplet wrt origin (0,0)

Prost !