C/C++ Programming interview questions and answers

What is the difference between a pointer and a reference? Ans- A reference must always refer to some object and, therefore, must always be initialized; pointers do not have such restrictions. A pointer can be reassigned to point to different objects while a reference always refers to an object with which it was initialized.


How are prefix and postfix versions of operator++() differentiated?
Ans- The postfix version of operator++() has a

dummy parameter of type int. The prefix version does not have dummy parameter.


What is name mangling in C++??
Ans- The process of encoding the parameter types with the function/method name into a unique name is called name mangling. The inverse process is called demangling.
For example Foo::bar(int, long) const is mangled as `bar__C3Fooil'.
For a constructor, the method name is left out. That is Foo::Foo(int, long) const is mangled as `__C3Fooil'.


What is the difference between const char *myPointer and char *const myPointer?
Ans- Const char *myPointer is a non constant pointer to constant data; while char *const myPointer is a constant pointer to non constant data.


How can I handle a constructor that fails?
Ans- throw an exception. Constructors don't have a return type, so it's not possible to use return codes. The best way to signal constructor failure is therefore to throw an exception.