C++ Dynamic Memory Allocation: Allocating memory for structure and user input

Last update on December 20 2024 12:22:41 (UTC/GMT +8 hours)

Write a C++ program to dynamically allocate memory for a structure and input its members from the user.

Sample Solution:

C Code:

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

// Defining a structure named MyStruct
struct MyStruct {
  int id;           // Integer member variable 'id'
  std::string name; // String member variable 'name'
  std::string country; // String member variable 'country'
};

int main() {
  // Dynamically allocate memory for a structure of type MyStruct
  MyStruct * EmployeeStruct = new MyStruct; // Allocating memory for a single instance of MyStruct

  // Input structure members from the user
  std::cout << "Employee ID (int value): ";
  std::cin >> EmployeeStruct->id; // Reading user input into the 'id' member of EmployeeStruct

  std::cout << "Input Employee name: ";
  std::cin.ignore(); // Ignoring the newline character from the previous input
  std::getline(std::cin, EmployeeStruct->name); // Reading user input into the 'name' member of EmployeeStruct

  std::cout << "Input Country name: ";
  std::getline(std::cin, EmployeeStruct->country); // Reading user input into the 'country' member of EmployeeStruct

  // Display the structure members
  std::cout << "\nEmployee Details:" << std::endl;
  std::cout << "ID: " << EmployeeStruct->id << std::endl; // Outputting the 'id' member of EmployeeStruct
  std::cout << "Name: " << EmployeeStruct->name << std::endl; // Outputting the 'name' member of EmployeeStruct
  std::cout << "Country: " << EmployeeStruct->country << std::endl; // Outputting the 'country' member of EmployeeStruct

  // Deallocate the dynamically allocated structure
  delete EmployeeStruct; // Deallocating the memory occupied by the EmployeeStruct pointer

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

Sample Output:

Employee ID (int value): 12
Input Employee name: Teuna Vinicio
Input Country name: France

Employee Details:
ID: 12
Name: Teuna Vinicio
Country: France

Explanation:

In the above exercise,

We define a structure called MyStruct with two members: id of type int and name of type std::string.
Inside the main() function, we use the new operator to dynamically allocate memory for a MyStruct structure. We assign its address to a pointer called dynamicStruct. This dynamically allocated structure resides in heap memory.
Next prompt the user to input the structure members: id, name and country using std::cin.
We then display the input structure members using std::cout and the arrow operator (->) to access the dynamic structure members.
Finally, we deallocate the dynamically allocated structure using the delete operator to free the memory occupied by the structure.

Flowchart:

CPP Code Editor:

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Next C++ Exercise: Linked list operations with memory allocation.