C++ Programming

Yes, the program will crash in an attempt to delete a null pointer.

Everything is correct, Only the first element of the array will be deleted”, The entire array will be deleted, but only the first element destructor will be called.

The best way to declare global variables is to declare them after including all the files so that it can be used in all the functions.

It depends on our requirement. When we are required an integer to be stored in 1 byte (means less than or equal to 255) we use short int, for 2 bytes we use int, for 8 bytes we use long int.

A char is for 1-byte integers, a short is for 2-byte integers, an int is generally a 2-byte or 4-byte integer (though not necessarily), a long is a 4-byte integer, and a long long is a 8-byte integer.

#define sq(x) x*x

Using extern in a function declaration we can make a function such that it can used outside the file in which it is defined.

An extern variable, function definition, or declaration also makes the described variable or function usable by the succeeding part of the current source file. This declaration does not replace the definition. The declaration is used to describe the variable that is externally defined.

If a declaration for an identifier already exists at file scope, any extern declaration of the same identifier found within a block refers to that same object. If no other declaration for the identifier exists at file scope, the identifier has external linkage.

Answer1

If you want the code to be even slightly readable, you will use typedefs.

typedef char* (*functiontype_one)(void);

typedef functiontype_one (*functiontype_two)(void);

functiontype_two myarray[N]; //assuming N is a const integral

Answer2

char* (* (*a[N])())()

Here a is that array. And according to question no function will not take any parameter value.

It tells the compiler that a variable or a function exists, even if the compiler hasn’t yet seen it in the file currently being compiled. This variable or function may be defined in another file or further down in the current file.

This is the way to initialize

a pointer to a function

void fun(int a)

{

}

void main()

{

void (*fp)(int);

fp=fun;

fp(1);

}

It depends on complier which may assign any garbage value to a variable if it is not initialized.

The throw operation calls the destructors for automatic objects instantiated since entry to the try block.

The default member and base-class access specifiers are different.

It permits a program to reference an identifier in the global scope that has been hidden by another identifier with the same name in the local scope.

By using the extern "C" linkage specification around the C function declarations.

Two.

There are two formats for initializers in C++ as shown in the example that follows. The first format uses the traditional C notation. The second format uses constructor notation.

int foo = 123;

int bar (123);

Default constructor WITH arguments

class B {

public:

B (int m = 0) : n (m) {}

int n;

};

int main(int argc, char *argv[])

{

B b;

return 0;

}

When you are designing a generic class to contain or otherwise manage objects of other types, when the format and behavior of those other types are unimportant to their containment or management, and particularly when those other types are unknown (thus, the genericity) to the designer of the container or manager class.

A specialized class "is" a specialization of another class and, therefore, has the ISA relationship with the other class. An Employee ISA Person. This relationship is best implemented with inheritance. Employee is derived from Person. A class may have an instance of another class. For example, an employee "has" a salary, therefore the Employee class has the HASA relationship with the Salary class. This relationship is best implemented by embedding an object of the Salary class in the Employee class.