Anyone have any clue what this error might actually mean? I'm tripping on a bit of code that can't seem to get around it. I've tried it with just h*2 instead of hprime, and just w*2 instead of wprime. Every time I get the same compiler (g++ compiler) error of :
grid.cpp: In constructor ‘Grid::Grid(int, int)’:
grid.cpp:34: error: ‘hprime’ cannot appear in a constant-expression
(the compiler doesn't always say hprime, it will say whatever variable is there, be it h or hprime or width). Any help would be greatly appreciated!
class Grid
{
public:
Grid(int x, int y);
~Grid();
void addObstacle(int w, int h);
void toString();
int** grid;
int height;
int width;
};
Grid::Grid(int w, int h)
{
width = w;
height = h;
const int hprime = h*2;
const int wprime = w*2;
grid = new int[wprime][hprime];
for(int x=0;x<wprime;x++) {
for (int y=0; y<hprime;y++) {
grid[x][y] = 0;<br>
}
}
}
You can't use new
to allocate a two-dimensional array, but you can change the offending line like this:
grid = new int*[wprime];
for (int i = 0 ; i < wprime ; i++)
grid[i] = new int[hprime];
If it doesn't have to be multidimensional, you can do:
grid = new int[wprime*hprime];
and just index it like
grid[A*wprime + B]
where you would normally index it like
grid[A][B]