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ReSharper & Implicitly Typed Variables

I am using ReSharper to help me spotting possible errors in my code, and, although not an error, it keeps complaining that I should use the var keyword instead of explicitly typing variables on the declaration. Personally, I think it is much more clear for me and for anyone reading my code if I write

IList<T> someVar = new List<T>();

instead of

var someVar = new List<T>();

Knowing that there're no performance differences between both ways, should I ignore these hints or stick with the var keyword?

Is it only a matter of taste or is it a good practice to implicitly type variables?

Solution

  • I see at least two reasons.

    First, its the matter of DRY principle: don't repeat yourself. If in future you decide to change type of variable from List<> to Stack<> or LinkedList<>, then with var you'd have to change in one place, otherwise you'd have to change in two places.

    Two, generic types declaration can be quite long. Dictionary<string, Dictionary<int, List<MyObject>>> anyone? This doesn't apply to simple List<T>, but you shouldn't have two code styles for different object types.