Guess the output?
#include<iostream>
class ArrayNotFound
{
private:
int m_id;
public:
ArrayNotFound(int id)
{
std::cout<<"ArrayNotFound
constructor called for ID: "<<id<<std::endl;
m_id=id;
}
~ArrayNotFound()
{
std::cout<<"ArrayNotFound
destructor called for ID: "<<m_id<<std::endl;
}
};
int main()
{
int c=1;
ArrayNotFound obj(1);
MyLabel:
ArrayNotFound obj2(2);
if(c == 1)
{
c=0;
goto MyLabel;
}
return 0;
}
Answer:
ArrayNotFound
constructor called for ID: 1
ArrayNotFound
constructor called for ID: 2
ArrayNotFound
destructor called for ID: 2
ArrayNotFound
constructor called for ID: 2
ArrayNotFound
destructor called for ID: 2
ArrayNotFound
destructor called for ID: 1
Explanation:
Whenever label is used
in the program, and if control of the program is returned due to goto statements
then destructor will be called for the objects declared under the label.
Since obj2 is declared
under the MyLabel destructor is called for that object. One should notice that destructor
is not called for obj because it is above the label statement. But destructor for
obj will be called once at the end of the main function block
Consider the following
statement,
MyLabel:
ArrayNotFound obj2(2);
if(c == 1)
{
c=0;
goto MyLabel; // Desctructor will be
called for obj2
}