Function names in C++: Capitalize or not? [closed]

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What's the convention for naming functions in C++?

I come from the Java environment so I usually name something 开发者_JAVA技巧like:

myFunction(...) {
}

I've seen mixed code in C++,

myFunction(....)
MyFunction(....)
Myfunction(....)

What's the correct way?

Also, is it the same for a class method as well as a non-class method?

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Since C++11, you may want to use either snake_case or camelCase for function names.

This is because to make a class work as the range-expression in a range-based for-loop, you have to define functions called begin and end (case-sensitive) for that class.

Consequently, using e.g. PascalCase for function names means you have to break the naming consistency in your project if you ever need to make a class work with the range-based for.

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There isn't a 'correct way'. They're all syntactically correct, though there are some conventions. You could follow the Google style guide, although there are others out there.

From said guide:

Regular functions have mixed case; accessors and mutators match the name of the variable: MyExcitingFunction(), MyExcitingMethod(), my_exciting_member_variable(), set_my_exciting_member_variable().

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Most code I've seen is camelCase functions (lower case initial letter), and ProperCase/PascalCase class names, and (most usually), snake_case variables.

But, to be honest, this is all just guidance. The single most important thing is to be consistent across your code base. Pick what seems natural / works for you, and stick to it. If you're joining a project in progress, follow their standards.

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The most common ones I see in production code are (in this order):

myFunctionName     // lower camel case

MyFunctionName     // upper camel case

my_function_name   // K & R ?

I find the naming convention a programmer uses in C++ code usually has something to do with their programming background.

E.g. ex-java programmers tend to use lower camel case for functions

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If you look at the standard libraries the pattern generally is my_function, but every person does seem to have their own way :-/

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Personally, I prefer thisStyle to ThisStyle for functions. This is really for personal taste, probably Java-influenced, but I quite like functions and classes to look different.

If I had to argue for it, though, I'd say that the distinction is slightly more than just aesthetic. It saves a tiny bit of thought when you come across function-style construction of a temporary. Against that, you can argue that it doesn't actually matter whether Foo(1,2,3) is a function call or not - if it is a constructor, then it acts exactly like a function returning a Foo by value anyway.

The convention also avoids the function-with-same-name-as-a-class-is-not-an-error fiasco that C++ inherits because C has a separate tag namespace:

#include <iostream>

struct Bar {
    int a;
    Bar() : a(0) {}
    Bar(int a) : a(a) {}
};

struct Foo {
    Bar b;
};

int Bar() {
    return 23;
}

int main() {
    Foo f;
    f.b = Bar();
    // outputs 23
    std::cout << f.b.a << "\n";
    // This line doesn't compile. The function has hidden the class.
    // Bar b;
}

Bar is, after all, both a noun and a verb, so could reasonably be defined as a class in one place and a function in another. Obviously there are better ways to avoid the clash, such as proper use of namespaces. So as I say, really it's just because I prefer the look of functions with lower-case initials rather than because it's actually necessary to distinguish them from from classes.

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Unlike Java, C++ doesn't have a "standard style". Pretty much very company I've ever worked at has its own C++ coding style, and most open source projects have their own styles too. A few coding conventions you might want to look at:

• GNU Coding Standards (mostly C, but mentions C++)
• Google C++ Style Guide
• C++ Coding Standards: 101 Rules, Guidelines, and Best Practices

It's interesting to note that C++ coding standards often specify which parts of the language not to use. For example, the Google C++ Style Guide says "We do not use C++ exceptions". Almost everywhere I've worked has prohibited certain parts of C++. (One place I worked basically said, "program in C, but new and delete are okay"!)

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I think its a matter of preference, although i prefer myFunction(...)

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As others said, there is no such thing in C++. Having said that, I tend to use the style in which the standard library is written - K & R.

Also, see the FAQ entry by Bjarne Stroustrup.

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Do as you wish, as long as your are consistent among your dev. group. every few years the conventions changes..... (remmeber nIntVAr)...

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There isn't so much a 'correct' way for the language. It's more personal preference or what the standard is for your team. I usually use the myFunction() when I'm doing my own code. Also, a style you didn't mention that you will often see in C++ is my_function() - no caps, underscores instead of spaces.

Really it is just dictated by the code your working in. Or, if it's your own project, your own personal preference then.

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It all depends on your definition of correct. There are many ways in which you can evaluate your coding style. Readability is an important one (for me). That is why I would use the my_function way of writing function names and variable names.