c++ allocate array on heap code example

Example 1: how to allocate on heap in c++

#include <iostream>
#include <string>

using String = std::string;
class Entity
{
private:
	String m_Name;
public:
	Entity() : m_Name("Unknown") {}
	Entity(const String& name) : m_Name(name) {}
	const String& GetName() const {
		return m_Name;
	};
};
int main() {
  // new keyword is used to allocate memory on heap
	int* b = new int; // new keyword will call the c function malloc which will allocate on heap  memory = data and return a ptr to that plaock of memory
	int* c = new int[50];
	Entity* e1 = new Entity;//new keyword Not allocating only memory but also calling the constructor
	Entity* e = new Entity[50];
	//usually calling new will  call underlined c function malloc
	//malloc(50); 
	Entity* alloc = (Entity*)malloc(sizeof(Entity));//will not call constructor only  allocate memory = memory of entity
	delete e;//calls a c function free
	Entity* e3 = new(c) Entity();//Placement New
}

Example 2: heap allocated array in c ++

//                                 Heap allocated array in c++
//using std::vector
#include <vector>
std::vector<myarray> bestArray(100); //A vector is a dynamic array, which (by default) allocates elements from the heap

//or managing memory yourself
myarray* heapArray = new myarray[100];
delete [] heapArray; // when you're done

//How to use vector to put elements inside the array.
// C++11:
std::vector<myarray> bestArray{ 1, 2, 3 };

// C++03:
std::vector<myarray> bestArray;
bestArray.push_back(myarray(1));
bestArray.push_back(myarray(2));
bestArray.push_back(myarray(3));