The reason is that const for the parameter only applies locally within the function, since it is working on a copy of the data. This means the function signature is really the same anyways. It’s probably bad style to do this a lot though. I personally tend to not use const except for reference and … Read more
I’m curious about the benefits/detriments of different constant declaration and definition options in C++. For the longest time, I’ve just been declaring them at the top of the header file before the class definition: While this pollutes the global namespace (which I know is a bad thing, but have never found a laundry list of … Read more
Your desire not to modify t is expressed in const T& t. The ending const specifies that you will not modify any member variable of the class abs belongs to. Since there is no class where this function belongs to, you get an error.
You should quote your array keys: As is, it was looking for constants called department, name, email, message, etc. When it doesn’t find such a constant, PHP (bizarrely) interprets it as a string (‘department’, etc). Obviously, this can easily break if you do defined such a constant later (though it’s bad style to have lower-case … Read more
Got it. I assumed it’d figure out that the > operator returned a bool (per documentation). But apparently it is not so.
JLS-8.3.1.1. static Fields says (in part) A static field, sometimes called a class variable, is incarnated when the class is initialized (§12.4). JLS-4.12.4. final Variables says (in part) A constant variable is a final variable of primitive type or type String that is initialized with a constant expression (§15.28) tl;dr Putting that together, a class constant is a static final field.
When relying upon ECMAScript 6 features such as const, you should set this option so JSHint doesn’t raise unnecessary warnings. /*jshint esnext: true */ (Edit 2015.12.29: updated syntax to reflect @Olga’s comments) This option, as the name suggests, tells JSHint that your code uses ECMAScript 6 specific syntax. http://jshint.com/docs/options/#esversion Edit 2017.06.11: added another option based on this answer. While inline … Read more
In python, I want a class to have some “constants” (practically, variables) which will be common in all subclasses. Is there a way to do it with friendly syntax? Right now I use: and I’m wondering if there is a better way to do it or a way to do it without then having to … Read more
const_iterators don’t allow you to change the values that they point to, regular iterators do. As with all things in C++, always prefer const, unless there’s a good reason to use regular iterators (i.e. you want to use the fact that they’re not const to change the pointed-to value).
declares ptr a pointer to const int type. You can modify ptr itself but the object pointed to by ptr shall not be modified. While declares ptr a const pointer to int type. You are not allowed to modify ptr but the object pointed to by ptr can be modified. Generally I would prefer the declaration like this which make it easy to read and understand (read from right to left):