Question

Say I got this C++ code:

class class1{     class2 *x; }  class class2{     class1 *x; } 

The compiler would give an error in line 2 because it couldn’t find class2, and the same if i switched the order of the classes. How do I solve this?

Answer 1

Two things – one, you need semicolons after class declarations:

class class1{     class2 *x; };  class class2{     class1 *x; }; 

Two, you can create a declaration in front of the definitions of the classes. That tells the compiler that this class exists, and you have yet to define it. In this case, put a class2 declaration in front of the definition of class1:

class class2 ;  class class1{     class2 *x; };  class class2{     class1 *x; };