Question

How do I check if a variable, specifically a pointer, is defined in C++? Suppose I have a class:

class MyClass {   public:      MyClass();      ~MyClass() {         delete pointer; // if defined!     }      initializePointer() {         pointer = new OtherClass();     }  private:      OtherClass* pointer;  }; 

Answer 1

Why worry about checking for the pointers value? Just initialize it to a null pointer value and then just call delete on it. delete on a null pointer does nothing (the standard guarantees it).

class MyClass {   public:      MyClass():pointer(0) { }      ~MyClass() {         delete pointer;         pointer = 0;     }      initializePointer() {         pointer = new OtherClass();     }  private:      OtherClass* pointer;  }; 

And everytime you call delete on it, you should set the pointer to a null pointer value. Then you are all fine.