Programming Fundamentals

A union definition itself is just a template or a type declaration; it does not allocate memory until a variable of that union type is instantiated.

 Macros execute faster than function calls. So, the given statement is true.

Passing by value creates a copy of the union. Modifying the copy does not change the original union variable in the calling function.

Macros are expanded inline by the preprocessor. This replaces the function call with the macro code, which can increase the size of the executable (code bloat) compared to a single function definition.

A union allocates enough memory for its largest member, and all members share the same memory location. Therefore, only one member can hold a valid value at any given time.

In C++, arguments are passed by value by default, meaning the function receives a copy of the original data. Changes made to the parameter inside the function do not affect the original variable unless pointers or references are used.

Passing a structure variable to a function is perfectly valid in C++. The structure is passed by value, creating a copy of the structure within the function scope.

The ternary operator (?:) is a built-in operator in C++ and cannot be overloaded.

To access a member of a structure using a pointer, the arrow operator (->) is used. However, if you have a direct structure variable, you use the dot operator (.) to access its members.

Destructors are called automatically when an object goes out of scope and they do not accept any parameters, nor do they return any value.

Constructors are special functions that initialize objects and are defined without any return type, not even void.