In C++, **int **is one of the most frequently used data type along with other data types like float, double, char, … . In this article, I will show you the way to know size of an **int **variable and what we can do with its size.

We can simply get size of an **int **variable using following code:

```
#include <iostream>
using namespace std;
int main()
{
cout << sizeof(int);
}
```

And we got result: 4 (bytes). So what can we do with this information ?

**1. Know the value range of an** **int variable**

As I have mentioned above, size of an **int **is 4 bytes, and because 1 byte equals to 8 bits, so that size of **int **is also 32 bits. So an **int **variable can represent **2 ^ 32 – 1 = 4294967295** values**.**

However, because an **int **variable can represent both negative and positive values so in fact, it can only represent numbers from** -2147483648 **to **2147483647 **(2^32 / 2 – 1).

In case of an **unsigned int **variable, as they can only hold values of non-negatives numbers so an **unsigned in** variable can represent number from **0 **to **4294967295** (2^32 – 1).

**2. Get the number of elements in an array**

If we know size of an element and size of the whole array, we can get the number of elements in the array using a simple arthimetic operation:

**Number of elements = Size of array / Size of an element**

Suppose that we have an array **arr**:

`int arr[] = {1, 2, 4, 5, 6, 3, 8, 9, 1, 2, 5, 7, 4, 3, 2, 4, 6, 7, 8, 9};`

Now we get size of the whole array (**arrSize**) and, because this is an array of integers, size of an **int **variable (**elementSize**).

```
int arrSize = sizeof(arr);
int elementSize = sizeof(int);
```

Finally, we can get the number of elements in the array:

`int n = arrSize / elementSize;`

Result: **20**

Here is the completed code:

```
#include <iostream>
using namespace std;
int main()
{
int arr[] = {1, 2, 4, 5, 6, 3, 8, 9, 1, 2, 5, 7, 4, 3, 2, 4, 6, 7, 8, 9};
int arrSize = sizeof(arr);
int elementSize = sizeof(int);
int n = arrSize / elementSize;
cout << n;
}
```

I have shown you the size of **int **variables in C++ and what we can do with size of a variable. I hope this article will help you in your carreer.

Happy coding !