Understanding find and vectors C++ [closed] - c++

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I'm trying to understand this line of code
vector<int>::iterator it = find(list_vector.begin(), list_vector.end(), 5)
where I have vector<int> list_vector; declared before hand.
What does the 5 do? What does it return? Does it return the 5 if it can find it at the beginning and end? If I wanted to make an if statement, and I wanted to find if the number 10 was in the statement (if it was, return true) how would I go about doing that?

Answer 1

vector<int>::iterator it = find(list_vector.begin(), list_vector.end(), 5)
std::find searches in the range defined by its first two arguments. It returns an iterator pointing to the first element that matches. If no element matches, it returns its 2nd parameter.
list_vector.begin() returns an iterator that points to the first element of list_vector.
list_vector.end() returns an iterator that points one element beyond the final element of list_vector.
5 is the target of the search. find() will look for an element that has the value 5.
If you'd like to determine if 10 is present anywhere in the vector, do this:
if(std::find(list_vector.begin(), list_vector.end(), 10) == list_vector.end())
std::cout << "No 10, bummer\n";
else
std::cout << "I found a 10!\n";
Or, if you'd like to simultaneously determine if 10 is present and determine its location:
std::vector<int>::iterator it = std::find(list_vector.begin(), list_vector.end(), 10);
if(it == list_vector.end())
std::cout << "No 10\n";
else
std::cout << "Look what I found: " << *it << "\n";