Question

Possible Duplicate:
C# 'var' vs specific type performance

Hi all,

I recently saw code that uses var a lot.

E.g.:

var myString = GetAnyString();
var myInstance = GetClass();

instead of

string myString = GetAnyString();
MyClass myInstance = GetClass();

Besides the readability (I think that using var is not very readable), are there any advantages and/or drawbacks using it? How about performance

Answer 1

var is replaced by the compiler with the right type, so there is no runtime performance hit, aside from a very small compile time overhead maybe (veeeeeeeery small).

Actually, from a readability point of vue, I personally do as follows:

• Variable instantiation: object myVar = new object();

• Variable propagation: var myVar = anotherVar.getComplexObject();

Also, you might be tempted to use them when you have a very complex type instantiation, like:

var myDict = new Dictionary<string, List<Tuple<string, object>>>();

Here, it really improves readability.