// Detail for Q&A: // Why is this printing '4232078'? (hex: 0x40939e) // https://www.sololearn.com/Discuss/608491/?ref=app #include using namespace std; class MyClass { private: // Run once. Then uncomment this for run 2. int myVar // = 1*256*256*256 + 2*256*256 + 3*256 + 4 // (01020304) ; public: MyClass(int a){ a = myVar; } int getMyVar(){ return myVar; // gets what's left over on bootstrap } }; int* ptrAtAddress(int where) { return reinterpret_cast(where); } int main() { // adding the function above (or vars with initialization) changes the returned constant for the Q&A, but we can still see where that constant arises MyClass myObj(7); MyClass myObj2(999); cout << hex; cout << "Q&A...why is it (hex): 0x" << myObj.getMyVar() << '\n'; cout << "myObj is allocated at: &"<< &myObj << '\n'; cout << "Value in memory at &0x28ff1c: 0x"<< *ptrAtAddress(0x28ff1c) << "\n\n"; cout << "Q&A...why is it (hex): 0x" << myObj2.getMyVar() << '\n'; cout << "myObj2 is allocated at: &"<< &myObj2 << '\n'; cout << "Value in memory at &0x28ff18: 0x"<< *ptrAtAddress(0x28ff18) << "\n\n"; cout << "This is a data structure (1 int)." << '\n'; cout << "* Proof: Uncomment '=...' on line 9." << '\n'; cout << "The data will change to 0x01020304" << "\n\n"; cout << "Notice how the objects are allocated 4 bytes apart\n"; cout << "Size of MyClass (static): " << sizeof(MyClass) << '\n'; cout << "Size of myObj (instance): "<< sizeof(myObj)<< endl; // flush }

Why is this printing... (detail)