Why should I use implicit types (var) when it is possible?

Question

Possible Duplicate:
Advantage of var keyword in C# 3.0

yesterday I stumbled upon a recomendation from MS, that I should use var, when ever possible:

http://msdn.microsoft.com/en-us/library/ff926074.aspx

I always thought that using the correct Type would help documenting the code and also help findig bugs at compile time.

What is the reason behind this recomendation?

Best Thomas

Answer 1

Using implicit typing does NOT mean that the variable is not strongly-typed. It means that the compiler implies the type from the right-hand side of the statement.

var i = 1;

i is defines as having type int. It's exactly the same as saying int i = 1; but the type is implied.

Similarly, the following code is a lot easier to read:

var pairs = new List<pair<int, IEnumerable<string>>>();

than if you had to type:

List<pair<int, IEnumerable<string>>> pairs = new List<pair<int, IEnumerable<string>>>();

and yet the results are exactly the same.