how to find element in vector in c++ code example

Example 1: vector.find()

#include <algorithm>
#include <vector>

if ( std::find(vec.begin(), vec.end(), item) != vec.end() )
   do_this();
else
   do_that();

Example 2: c++ find element in vector

auto it = find(vec.begin(),vec,end(), item)!
if(it != vec.end()){
 	 int index = it - vec.begin();
}