C++ Programming Fundamentals

FORTRAN (FORmula TRANslation), developed by IBM and John Backus's team and released in 1957, was the first widely successful high-level programming language. It enabled scientists and engineers to write code using mathematical notation rather than assembly or machine code. C (1970s) and C++ (1980s) came decades later, while QBASIC was a 1990s educational language.

The global constant x=5 is declared at file scope. Inside main(), 'int x[x]' creates an array of size 5 (using the global x, not a VLA since x is a constant). The local x (the array name) shadows the global x within main. 'sizeof(x)' returns the size of the local array (5 * sizeof(int) = 20 on most systems). Dividing by sizeof(int) gives 5. The local array declaration doesn't affect the global constant.

This code is valid C++ (not C). 'int x = 5' declares a global variable x. 'class x' declares a class named x. In main(), 'class x y' declares a variable y of type class x. In C++, variable names and class/struct names occupy different namespaces, so 'int x' and 'class x' don't conflict. The code compiles successfully, making the answer True.

The array member of the struct is declared using the global constant SIZE which equals 5. Inside the member function size, sizeof(array) evaluates to 5 times the size of an integer, and dividing by sizeof(int) yields 5. The inner enum declaration defining SIZE as 3 hides the global constant in some contexts, but does not affect the array size determined at class scope definition.

In C++, you cannot declare an array of references. 'int& x[50]' attempts to create an array of 50 references to int, which is syntactically illegal. References must be initialized upon declaration and cannot be reseated, making arrays of references impossible. This code will not compile, so the statement is False.

When a user-declared constructor is defined, the compiler stops generating the default constructor. This struct has two user-declared constructors: a copy constructor 'A(A& a)' and a converting constructor 'A(double d)'. Because at least one constructor is explicitly declared, the compiler will NOT generate any additional constructors (no default constructor, no copy constructor since one exists, no move constructors). Therefore, the number of implicitly-defined constructors is 0.

The local declaration int x = x; shadows the global x. The local x is initialized with its own, as-yet uninitialized value, resulting in undefined behavior and an indeterminate value. The global x = 5 is completely ignored.