C++ Programming Question:
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What is a dangling pointer in C++?
Answer:
A dangling pointer arises when you use
the address of an object after
its lifetime is over. This may occur
in situations like returning
addresses of the automatic variables
from a function or using the
address of the memory block after
it is freed. The following
code snippet shows this:
class Sample
{
public:
int *ptr;
Sample(int i)
{
ptr = new int(i);
}
~Sample()
{
delete ptr;
}
void PrintVal()
{
cout << "The value is " << *ptr;
}
};
void SomeFunc(Sample x)
{
cout << "Say i am in someFunc " << endl;
}
int main()
{
Sample s1 = 10;
SomeFunc(s1);
s1.PrintVal();
}
In the above example when PrintVal() function is
called it is called by the pointer that has been
freed by the destructor in SomeFunc.
the address of an object after
its lifetime is over. This may occur
in situations like returning
addresses of the automatic variables
from a function or using the
address of the memory block after
it is freed. The following
code snippet shows this:
class Sample
{
public:
int *ptr;
Sample(int i)
{
ptr = new int(i);
}
~Sample()
{
delete ptr;
}
void PrintVal()
{
cout << "The value is " << *ptr;
}
};
void SomeFunc(Sample x)
{
cout << "Say i am in someFunc " << endl;
}
int main()
{
Sample s1 = 10;
SomeFunc(s1);
s1.PrintVal();
}
In the above example when PrintVal() function is
called it is called by the pointer that has been
freed by the destructor in SomeFunc.
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