what is string::npos code example

Example 1: npos in cpp

found = str.find(str2);

if (found != std::string::npos)
    std::cout << "first 'needle' found at: " << int(found) << std::endl;

Example 2: what is string::npos

npos is a constant static member value with the greatest possible value for an element of type size_t. This value, when used as the value for a len parameter in string's member functions, means until the end of the string. ... As a return value, it is usually used to indicate that no matches were found in the string