C++ | Constructors | Question 16

Predict the output of following program?

#include <iostream>
using namespace std;
class Test
{
private:
    int x;
public:
    Test(int i)
    {
        x = i;
        cout << "Called" << endl;
    }
};

int main()
{
    Test t(20);
    t = 30; // conversion constructor is called here.
    return 0;
}

(A) Compiler Error
(B)

Called
Called

(C)

Called

Answer: (B)

Explanation: If a class has a constructor which can be called with a single argument, then this constructor becomes conversion constructor because such a constructor allows automatic conversion to the class being constructed.

A conversion constructor can be called anywhere when the type of single argument is assigned to the object. The output of the given program is

Called
Called

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