class SECTOR { public: int numTriangles; TRIANGLE *triangle; }; ... SECTOR sector1; ... sector1.triangle = new TRIANGLE[numTriangles]; When that is called it creates a runtime error that says : Invalid allocation size: blah bytes could someone tell me whats wrong and the right way to define at runtime a certain number of triangles? NARF - Pinky and the Brain

Have you initialized numTriangles?

yes

NARF -
Pinky and the Brain

There''s nothing wrong with the code you presented unless you misunderstood Raloth''s question. Try this out

SECTOR s;s.numTriagles = 10; //this is what initialization is abouts.triangle = new TRIANGLE[s.numTriagles];

wow... so simple yet so complicated ... but thanks!

NARF -
Pinky and the Brain