'What are helper functions in C++?
I was trying to understand what "helper functions" are in C++ from "The C++ Programming Language" by Bjarne Stroustrup. But the book hasn't explained anything about it and the purpose of using it in classes. I tried searching for it on Web and found this [note: dead link]. I have got the gist of it but still unclear about what is the real purpose of helper functions, when should I use them and on the whole, what are helper functions?
Solution 1:[1]
There is a great definition of a helper function from the CppCoreGuidline:
A helper function is a function (usually supplied by the writer of a class) that does not need direct access to the representation of the class, yet is seen as part of the useful interface to the class. Placing them in the same namespace as the class makes their relationship to the class obvious and allows them to be found by argument dependent lookup.
For more info you can check the paragraph with a clear example, from which the upper quote is taken.
Solution 2:[2]
An example could be the input validation function that you will be reusing in the entire main function. Let's say you have a program that asks for the user's age, since age is an integer > 0, you'll need to have a separate function that takes care of the "cin >> users_age;". If the input satisfies the condition statement then proceed, otherwise ask the user to re-enter their age.
This is just an example of "helper function". Correct me readers if I'm wrong. Thanks!
Solution 3:[3]
"Helper functions" are described in Bjarne Stroustrups book, and I was just reading about them yesterday. According to Stroustrup good design of a class should keep the number of functions implementing a class to a minimum. You dont want to have 50 functions in a class, according to Stroustrup. Instead you use "helper functions" that use the class interface (call the member functions). They could perhaps (not sure about this) be defined in a shared namespace to give meaning to their "relationship". You can find the paragraph in the book in chapter 9 section 9.7.5
Sources
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Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Oleh Holovko |
| Solution 2 | Ben10_nf. |
| Solution 3 |