Question

I’m having a very strange issue with a space invaders game I’m working on. Basically I get an access violation error:

Unhandled exception at 0x5edad442 (msvcr100d.dll) in
SpaceInvaders.exe: 0xC0000005: Access violation reading location
0x00000000.

when I include the piece of code below. visual studio takes me to “strcmp.asm” when debugging. Note that Im not using strcmp() in any of my code. Is there anything wrong with the code, or is this a problem beyond the scope of what I’ve included? Thanks for any help

const char* invarray[] = {"invader0.png", "invader1.png", "invader2.png", "invader3.png", "invader4.png"}; 
int i=0;
//Creates 55 invaders
for (int y=0; y<250; y+=50){
    for (int x=0; x<550;x+=50){
        Invader inv(invarray[y/50], x+50, y+550, 15, 15, 1, false, 250);
        invaders[i] = inv;
    }
}

Invader constructor:

Invader::Invader(const char *pic, int x, int y, int w, int h, bool dir, bool des, int point) : MovingObject(pic, x, y, w, h) , direction(dir), destroyed(des), b(0), points(point){};

MovingObject Constructor

MovingObject::MovingObject(const char *pic, int x, int y, int w, int h):picture(pic), positionX(x), positionY(y), width(w), height(h) {};

Answer 1

This line looks suspicious:

invaders[i] = inv;

You’re never incrementing i, so you keep assigning to invaders[0]. If this is just an error you made when reducing your code to the example, check how you calculate i in the real code; you could be exceeding the size of invaders.

If as your comment suggests, you’re creating 55 invaders, then check that invaders has been initialised correctly to handle this number.