The difference is that const char * is a pointer to a const char, while char * const is a constant pointer to a char. The first, the value being pointed to can’t be changed but the pointer can be. The second, the value being pointed at can change but the pointer can’t (similar to … Read more
You should declare your constant string as follows: NSString * const kSomeConstantString = @””; // constant pointer instead of: const NSString * kSomeConstantString = @””; // pointer to constant // equivalent to NSString const * kSomeConstantString = @””; The former is a constant pointer to an NSString object, while the latter is a pointer to … Read more
That is perfectly acceptable, probably even the standard. (public/private) static final TYPE NAME = VALUE; where TYPE is the type, NAME is the name in all caps with underscores for spaces, and VALUE is the constant value; I highly recommend NOT putting your constants in their own classes or interfaces. As a side note: Variables … Read more
Here’s a few things you could do: Export a const from the module. Depending on your use case, you could just: export const constant1 = 33; And import that from the module where necessary. Or, building on your static method idea, you could declare a static get accessor: const constant1 = 33, constant2 = 2; … Read more
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) /*jshint esversion: 6 */ const Suites = { Spade: 1, Heart: 2, Diamond: 3, Club: 4 }; This option, as the name suggests, … Read more
There are two aspects to your questions: what are the technical aspects of using const instead of var and what are the human-related aspects of doing so. The technical difference is significant. In compiled languages, a constant will be replaced at compile-time and its use will allow for other optimizations like dead code removal to … Read more
A const object is always static.
consts are compile time constants. Meaning that their value has to be assigned during compile time, unlike vals, where it can be done at runtime. This means, that consts can never be assigned to a function or any class constructor, but only to a String or primitive. For example: const val foo = complexFunctionCall() //Not … Read more
There is a post on dart’s website and it explains it pretty well. Final: “final” means single-assignment: a final variable or field must have an initializer. Once assigned a value, a final variable’s value cannot be changed. final modifies variables. Const: “const” has a meaning that’s a bit more complex and subtle in Dart. const … Read more
I believe there is a difference. Let’s rename them so that we can talk about them more easily: const double PI1 = 3.141592653589793; constexpr double PI2 = 3.141592653589793; Both PI1 and PI2 are constant, meaning you can not modify them. However only PI2 is a compile-time constant. It shall be initialized at compile time. PI1 … Read more