C++ Function Overloading and Default Arguments

Output? CPP

#include<iostream>
using namespace std;

int fun(int x = 0, int y = 0, int z)
{  return (x + y + z); }

int main()
{
   cout << fun(10);
   return 0;
}

What is the output of this C++ program?

#include 
using namespace std;
void square (int *x)
{
*x = (*x)++ * (*x);
}
void square (int *x, int *y)
{
*x = (*x) * --(*y);
}
int main ( )
{
int number = 30;
square(&number, &number);
cout << number;
return 0;
}

Which of the following in Object Oriented Programming is supported by Function overloading and default arguments features of C++.

Which of the following overloaded functions are NOT allowed in C++? 1) Function declarations that differ only in the return type

    int fun(int x, int y);
         void fun(int x, int y); 

2) Functions that differ only by static keyword in return type

    int fun(int x, int y);
         static int fun(int x, int y); 

3)Parameter declarations that differ only in a pointer * versus an array []

int fun(int *ptr, int n);
int fun(int ptr[], int n); 

4) Two parameter declarations that differ only in their default arguments

int fun( int x, int y); 
int fun( int x, int y = 10); 

Output of following program? CPP

#include <iostream>
using namespace std;

int fun(int=0, int = 0);

int main()
{
  cout << fun(5);
  return 0;
}

int fun(int x, int y) { return (x+y); }

Predict the output of following C++ program? C

include<iostream>
using namespace std;
 
class Test
{
protected:
    int x;
public:
    Test (int i):x(i) { }
    void fun() const  { cout << "fun() const " << endl; }
    void fun()        {  cout << "fun() " << endl;     }
};
 
int main()
{
    Test t1 (10);
    const Test t2 (20);
    t1.fun();
    t2.fun();
    return 0;
}