C++ Dynamic Memory Allocation: Creating Objects with new Operator

Last update on April 12 2025 12:57:51 (UTC/GMT +8 hours)

5. Dynamically Create an Object of a Class Using New

Write a C++ program to dynamically create an object of a class using the new operator.

Sample Solution:

C Code:

#include <iostream>  // Including the Input/Output Stream Library

class MyClass {  // Declaration of a class named MyClass
public:
  void displayMessage() {  // Public member function within the class MyClass
    std::cout << "Dynamic object!" << std::endl;  // Outputting a message
  }
};

int main() {
  // Create a dynamic object of MyClass
  MyClass * dynamicObject = new MyClass;  // Dynamically allocating memory for an object of type MyClass

  // Call the member function of the dynamic object
  dynamicObject -> displayMessage();  // Accessing the member function of the dynamically created object using the pointer to the object

  // Deallocate the dynamic object
  delete dynamicObject;  // Deallocating the memory occupied by the dynamic object

  return 0;  // Returning 0 to indicate successful execution of the program
}

Sample Output:

Dynamic object!

Explanation:

In the above exercise,

• At first we define a class called MyClass with a member function displayMessage() that simply outputs a message.
• Inside the main() function, we use the new operator to dynamically create an object of MyClass and assign its address to a pointer called dynamicObject. This dynamically created object resides in the heap memory.
• Then use the arrow operator (->) to call the displayMessage() member function of the dynamic object.
• Finally, deallocate the dynamically created object using the delete operator to free the memory occupied by the object.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to define a simple class with member variables and methods, then dynamically create an object and call its methods.
• Write a C++ program that dynamically allocates an object of a class representing a complex number and prints its real and imaginary parts.
• Write a C++ program to create a class for a student record, dynamically allocate an object, assign values using member functions, and display the record.
• Write a C++ program that uses the new operator to dynamically allocate an object of a class with a constructor and destructor, then prints a message upon creation and deletion.

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