What are the main types of errors in C programming?

Which of these C preprocessor directive syntaxes are correct?

A pointer to a pointer is a form of:

In Object-Oriented Programming (OOP), the decomposition of a problem into a number of entities is called as

Constructors __________ to allow different approaches of object construction.

What is the output of the following C code?

#include<stdio.h>

int main()

{

    int a=6;

    int *p=&a;

    (*p)++;

    printf("%d",*p);

    return 0;

}

What is the correct function prototype for overloading the () operator?

What will be the output of the following C++ code?

#include <iostream>
#include <utility>

using namespace std;

int main()
{
pair<int, int> p(1, 2);
cout << "Pair(first,second) = (" << p.first << "," << p.second << ")
";
return 0;
}

What will be the output of the following C++ code?

#include<iostream>
using namespace std;
class Base
{
public:
virtual void show() { cout<<" In Base \n"; }
};
class Derived: public Base
{
public:
void show() { cout<<"In Derived \n"; }
};
int main(void)
{
Base *bp = new Derived;
bp->show();
Base &br = *bp;
br.show();
return 0;
}