Check all the elements in an array are even using library in C++

We are given an array of elements and we have to check the whether each element is even or not. 

Examples:

Input : [2, 4, 6, 8, 9]
Output : All the elements are not even

Input : [4, 6, 8, 12, 14]
Output : All the elements are even

Approach: The above problem can be solved using for loop but in C++ we have all_of() algorithm which operates on whole array and save time to write code for loop and checks each element for the specified property. 

Note that all_of() also uses loop internally, it just saves our time of writing a loop code. 

CPP

// CPP program to check if all elements
// of an array are even or odd.
#include <algorithm>
#include <iostream>
using namespace std;

void even_or_not(int arr[], int len)
{
    // all_of() returns true if given operation is true
    // for all elements, otherwise returns false.
    all_of(arr, arr + len, [](int i) { return i % 2; }) ?
                        cout << "All are even elements" :
                        cout << "All are not even elements";
}

int main()
{
    int arr[] = { 2, 4, 6, 12, 14, 17 };
    int len = sizeof(arr) / sizeof(arr[0]);
    even_or_not(arr, len);
    return 0;
}

Output:

All are not even elements