index of in cpp code example

Example 1: get index of value c++

vector<int> arr = { 6, 3, 5, 2, 8 };
vector<int>::iterator itr = std::find(arr.begin(), arr.end(), elem);

if (itr != end(arr)) {
	cout << "Element " << elem << " is present at index " << distance(arr, itr) << " in the given array";
}
else {
	cout << "Element is not present in the given array";
}

Example 2: find in string c++

size_t find (const string& str, size_t pos = 0) const;