# Sort an array in ascending order using sort() function in C++ STL

C++ STL - sort() function Example: In this article, we are going to learn how to sort array elements in Ascending Order using sort() function of C++ - STL?
Submitted by IncludeHelp, on January 03, 2018

## Problem statement

Given an array and we have to sort the elements in Ascending Order using C++ STL sort() function.

## How to Sort an Array in Ascending order using STL in C++?

To sort an array in ascending order using STL in C++, use the sort() function.

It is a built-in function of algorithm header file it is used to sort the containers like array, vectors in specified order.

### Syntax

```sort(first, last);
```

### Parameter(s)

• first - is the index (pointer) of first element from where we want to sort the elements.
• last - is the last index (pointer) of last element.

For example, we want to sort elements of an array ‘arr’ from 1 to 5 position, we will use sort(arr, arr+5) and it will sort 5 elements in Ascending order.

### Sample Input and Output

```Input:
Array: 10, 1, 20, 2, 30

Output:
Sorted Array: 1, 2, 10, 20, 30
```

## C++ program to sort an array in ascending order

```#include <algorithm>
#include <iostream>
using namespace std;

int main() {
// declare and define an array
int arr[] = {10, 1, 20, 2, 30};

// size of the array
// total size/size of an element
int size = sizeof(arr) / sizeof(int);

// calling sort() to sort array elements
sort(arr, arr + 5);

// printing sorted elements
cout << "Sorted elements are: ";
for (int i = 0; i < size; i++) cout << arr[i] << " ";

return 0;
}
```

### Output

```Sorted elements are: 1 2 10 20 30
```