Advantages of using const instead of variables inside methods

Asked 2011-04-29T15:17:53.090

Whenever I have local variables in a method, ReSharper suggests to convert them to constants:

// instead of this:
var s = "some string";
var flags = BindingFlags.Public | BindingFlags.Instance;

// ReSharper suggest to use this:
const string s = "some string";
const BindingFlags flags = BindingFlags.Public | BindingFlags.Instance;

Given that these are really constant values (and not variables) I understand that ReSharper suggest to change them to const.

But apart from that, is there any other advantage when using const (e.g. better performance) which justifies using const BindingFlags instead of the handy and readable var keyword?

BTW: I just found a similar question here: Resharper always suggesting me to make const string instead of string, but I think it is more about fields of a class where my question is about local variable/consts.

c# coding-style resharper constants

Edit Report

2 Answers

As per my understanding Const values do not exist at run time - i.e. in form of a variable stored in some memory location - they are embeded in MSIL code at compile time . And hence would have an impact on performance. More over run-time would not be required to perform any house keeping (conversion checks / garbage collection etc) on them as well, where as variables require these checks.

answered 2011-04-29T15:49:45.913

The const keyword tells the compiler that it can be fully evaluated at compile time. There is a performance & memory advantage to this, but it is small.

answered 2011-04-29T15:28:27.290

Advantages of using const instead of variables inside methods

2 Answers

Your Answer