# Get first and last elements from Array and Vector in CPP

• Last Updated : 10 Nov, 2018

Given an array, find first and last elements of it.

```Input: {4, 5, 7, 13, 25, 65, 98}
Output: First element: 4
Last element: 98
```

In C++, we can use sizeof operator to find number of elements in an array.

 `// C++ Program to print first and last element in an array``#include ``using` `namespace` `std;``int` `main()``{``    ``int` `arr[] = { 4, 5, 7, 13, 25, 65, 98 };``    ``int` `f, l, n;``    ``n = ``sizeof``(arr) / ``sizeof``(arr[0]);``    ``f = arr[0];``    ``l = arr[n - 1];``    ``cout << ``"First element: "` `<< f << endl;``    ``cout << ``"Last element: "` `<< l << endl;``    ``return` `0;``}`

Output:

```First element: 4
Last element: 98
```

We should not sizeof when arrays are passed as parameters, there we must pass size and use that size to find first and last elements.

 `// C++ Program to print first and last element in an array``#include ``using` `namespace` `std;`` ` `int` `printFirstLast(``int` `arr[], ``int` `n)``{``    ``int` `f = arr[0];``    ``int` `l = arr[n - 1];``    ``cout << ``"First element: "` `<< f << endl;``    ``cout << ``"Last element: "` `<< l << endl;``}`` ` `int` `main()``{``    ``int` `arr[] = { 4, 5, 7, 13, 25, 65, 98 };``    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr[0]);``    ``printFirstLast(arr, n);``    ``return` `0;``}`

Output:

```First element: 4
Last element: 98
```

In case of vectors in C++, there are functions like front and back to find first and last elements.

 `// C++ Program to find first and last elements in vector``#include ``#include ``using` `namespace` `std;``int` `main()``{``    ``vector<``int``> v;`` ` `    ``v.push_back(4);``    ``v.push_back(5);``    ``v.push_back(7);``    ``v.push_back(13);``    ``v.push_back(25);``    ``v.push_back(65);``    ``v.push_back(98);``    ``cout << ``"v.front() is now "` `<< v.front() << ``'\n'``;``    ``cout << ``"v.back() is now "` `<< v.back() << ``'\n'``;``    ``return` `0;``}`

Output:

```v.front() is now 4
v.back() is now 98
```

We can use front and back even when vector is passed as a parameter.

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