## new

The `new` operator allows us to allocate a certain amount of memory on the fly. Let's allocate 4 bytes:
```
new int; // int type contains 4 bytes
```

The code will compile, but we won't get anything from it, because the `new` operator returns the address of the allocated memory. To use this memory, the address must be stored somewhere. Here we need pointers!
```
int* ptr = new int; // ptr is containing the address of allocated memory 
```

Now let's use the allocated memory to store the number 200 there:
```
int* ptr = new int; 
*ptr = 200;
```
Let's display the number 200 on the screen through the pointer:


I2luY2x1ZGUgPGlvc3RyZWFtPgoKaW50IG1haW4oKQp7CiAgICB1c2luZyBzdGQ6OmNvdXQ7CiAgICB1c2luZyBzdGQ6OmVuZGw7CgogICAgaW50KiBwdHIgPSBuZXcgaW50OyAvLyAicHRyIiBpcyBjb250YWluaW5nIHRoZSBhZGRyZXNzIG9mIGFsbG9jYXRlZCBtZW1vcnkgCiAgICAqcHRyID0gMjAwOwoKICAgIGNvdXQgPDwgIkFkZHJlc3Mgb2YgYWxsb2NhdGVkIG1lbW9yeTogIiA8PCBwdHIgPDwgZW5kbDsKICAgIGNvdXQgPDwgIlZhbHVlIGJ5IGFkZHJlc3M6ICIgPDwgKnB0ciA8PCBlbmRsOwogICAgY291dCA8PCAgcHRyIDw8ICIgLS0tPiAiIDw8ICpwdHIgPDwgZW5kbDsKCiAgICByZXR1cm4gMDsKfQ==

When you dynamically create a variable, you can initialize it explicitly, that is, lines 8 and 9 can be replaced with one:
```
int* ptr = new int (200); // or int* ptr = new int {200}; 
```
>Note
>
>The C++ language does not have a garbage collector, which is why the programmer must free the occupied memory manually. 


## delete

After we have used the allocated memory, it should be cleared using the `delete` operator:


I2luY2x1ZGUgPGlvc3RyZWFtPgoKaW50IG1haW4oKQp7CiAgICB1c2luZyBzdGQ6OmNvdXQ7CiAgICB1c2luZyBzdGQ6OmVuZGw7CgogICAgaW50KiBwdHIgPSBuZXcgaW50ICgyMDApOyAKCiAgICBjb3V0IDw8ICJBZGRyZXNzIG9mIGFsbG9jYXRlZCBtZW1vcnk6ICIgPDwgcHRyIDw8IGVuZGw7CiAgICBjb3V0IDw8ICJWYWx1ZSBieSBhZGRyZXNzOiAiIDw8ICpwdHIgPDwgZW5kbDsKICAgIGNvdXQgPDwgIHB0ciA8PCAiIC0tLT4gIiA8PCAqcHRyIDw8IGVuZGw7CgogICAgZGVsZXRlIHB0cjsgLy8gdXNpbmcgZGVsZXRlIGZvciBmcmVlaW5nIGFsbG9jYXRlZCBtZW1vcnkKCiAgICByZXR1cm4gMDsKfQ==

In fact, the `delete` operator does not delete, but returns the allocated memory back to the system. The C++ language makes no guarantees about what will happen to the contents of the freed memory.


A pointer that points to memory freed by the `delete` operator is called a dangling pointer. Trying to dereference or access memory through a dangling pointer will produce unexpected results:


I2luY2x1ZGUgPGlvc3RyZWFtPgoKaW50IG1haW4oKQp7CiAgICB1c2luZyBzdGQ6OmNvdXQ7CiAgICB1c2luZyBzdGQ6OmVuZGw7CgogICAgaW50KiBwdHIgPSBuZXcgaW50KDkpOwoKICAgIGRlbGV0ZSBwdHI7CgogICAgY291dCA8PCIqcHRyOiAiIDw8ICpwdHIgPDwgZW5kbDsgCgogICAgY291dCA8PCIgcHRyOiAiIDw8IHB0ciA8PCBlbmRsOyAKCiAgICByZXR1cm4gMDsKfQ==

So that the remote pointer does not interfere with us, it must be made `null` using the `nullptr`.

In this section, we will learn the structure of a default C++ program.

In this section, we will learn how to manipulate different variables.

In this section, we will learn how to equate and compare variables, and use mathematical and bitwise operators.

In this section, we will learn how to control the flow of our programs.

In this section, we will explore the concept of functions, and how to create and call them.

In this section, we will understand how to allocate memory, how to use memory by pointers help.