in c++ how is memory allocated on the heap
In C++, memory can be dynamically allocated on the heap using the `new` operator. When you use `new` to allocate memory, it requests a block of memory from the heap that is large enough to store the specified data type or object.
Here is the syntax for allocating memory on the heap in C++:
```cpp
<datatype>* pointer_name = new <datatype>;
```
For example, to dynamically allocate an integer on the heap:
```cpp
int* numPtr = new int;
```
In this example, `new int` requests memory for storing an integer on the heap and returns a pointer to the allocated memory. The `int*` declares a pointer named `numPtr` to hold the address of the allocated memory.
To allocate memory for an array, the syntax is slightly different:
```cpp
<datatype>* pointer_name = new <datatype>[size];
```
For example, to dynamically allocate an array of integers with a size of 5:
```cpp
int* arrPtr = new int[5];
```
In this case, `new int[5]` requests memory to store an array of 5 integers on the heap and returns a pointer to the first element of the allocated memory. The `int*` declares a pointer named `arrPtr` to hold the address of the allocated memory.
Remember, when you allocate memory on the heap using `new`, it is your responsibility to deallocate it using the `delete` operator once you no longer need it. This prevents memory leaks and frees up the allocated memory for future use.