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New is used to dynamically allocate memory in C++. It will also call the default constructor of a class that is created with it.

int *array; // First declare a pointer

array = new int [5] // Allocate enough memory for a 5 element int array

// To deallocate your memory when you are finished with it, you must call delete on your pointer

delete[] array;

myClassType *mct = new myClassType; // example for class

...

delete mct; // class delete

The virtual keyword means that the class has a static virtual table (vtable) containing function pointers for each type of the class. This enables polymorphism by allowing a pointer to the base class to be assigned an address of any instance of the class in the hierarchy, and then invoking a method through that pointer - which will properly choose the correct method for that class type. Virtual also ensures that the constructors and destructors are invoked in the correct order.

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Q: What is the use of keyword virtual?
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what is the use of new keyword in awt programming


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The lazy way is to use a dynamic cast. The correct way is to use virtual functions in the base class. That way you don't ever need to know the derived type -- it simply does what is expected of it.


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Related questions

What is the use of keyword new used in AWT programming?

what is the use of new keyword in awt programming


Which keyword do you use to deallocate memory that has been assigned to a stream object?

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