Question

What will be displayed:

#include 

class A
{
    public:
    A() { std::cout << "A()"; }

    A(const A& a){ std::cout << "copyA()"; }

    A& operator=(const A& a)
    {
        std::cout << "=()";
    }
};

int main()
{
    A a1;
    A a2 = a1;
}

Cosmo · Accepted Answer

Program displays:

A()copyA()

Copy-constructor is called when a new object is created from an existing object, as a copy of the existing object. And assignment operator is called when an already initialized object is assigned a new value from another existing object.


a2 = a1;  // calls assignment operator, same as "a2.operator=(a1);"

A a3 = a1;  // calls copy constructor, same as "A a3(a1);"

Cosmo · Accepted Answer

<pre><code>A()copyA()</code></pre>

Cosmo · Answer

Cosmo · Answer

A()copyA()=()

Cosmo · Answer

Cosmo · Answer

A()A()copyA()=()

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