(Local Variable Destructors) Write a program illustrating that all destructors for objects constructed in a block are called before an exception is thrown from that block.

Question

What will be an ideal response?

Answer 1

```
// Class TestObject definition.
class TestObject
{
public:
TestObject( int ); // constructor takes int parameter
~TestObject(); // destructor
private:
int value;
}; // end class TestObject
```
```
// Class TestObject member function definition.
#include
#include "TestObject.h"
using namespace std;

// constructor takes int parameter
TestObject::TestObject( int val ) : value( val )
{
cout << "TestObject " << value << " constructor\n";
} // end TestObject constructor

// destructor
TestObject::~TestObject()
{
cout << "TestObject " << value << " destructor\n";
} // end TestObject destructor
```
```
#include
#include
using namespace std;

#include "TestObject.h"

int main()
{
try // create objects and throw exception
{
// create three TestObjects
TestObject a( 1 );
TestObject b( 2 );
TestObject c( 3 );
cout << '\n';

// throw an exception to show that all three Objects created above
// will have their destructors called before the block expires
throw runtime_error( "This is a test exception" );
} // end try

// catch the Error
catch ( runtime_error &exception )
{
cerr << exception.what() << "\n";
} // end catch

return 0;
} // end main
```
TestObject 1 constructor
TestObject 2 constructor
TestObject 3 constructor
TestObject 3 destructor
TestObject 2 destructor
TestObject 1 destructor
This is a test exception