How to find out if an item is present in an std vector

Question

All I want to do is see if an element in the vector exists or not, so I can deal with each instance individually.

Answer 1

The most straightforward solution is to count the total number of elements in the vector that have the specified value. 

If the count is greater than zero, we've found our element. 

This is simple to accomplish with the std::count function.

#include <iostream>

#include <vector>

#include <algorithm>


int main()

{

    std::vector<int> v = { 4, 7, 5, 2, 6, 9 };

    int key = 6;


    if (std::count(v.begin(), v.end(), key)) {

        std::cout << "Element found";

    }

    else {

        std::cout << "Element not found";

    }


    return 0;

}