What is the correct example of string data types?

Question

the example of string data type is wrong it is saying no output

Answer 1

Since you tagged C++ in your question, you need to know that String is not a data type in C++, but a class. This class is found inside the C++ Standard Library (std).
C++ does have a C way of representing a string as an array that is marked at the end with '\0'(null character).
So you either have : char hello[6] = {'h', 'e', 'l', 'l', 'o', '\0'}
or you have string str = "hello"

Hope that clarifies things.