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Usage of the C# var keyword. Is there a Best Practice?



1) To limit redundant code, such as:



Dictionary< string , List< int , bool >> myDictionary = new Dictionary< string , List< int , bool >>();



var myDictionary = new Dictionary< string , List< int , bool >>();

2) To support anonymous types, which were necessary to implement LINQ, such as:



var car = new { Make = "Toyota" , Model = "Camry" };



Now, much of the code you see floating around on the Internet coming from experts use vars just about anywhere where it can be used. However, I have developed a personal preference, i.e. best practice if you will, that goes like this:



Value types, such as, int, bool, float, and string (as an exception) are explicity declared.

Reference types are declared with var. Is there anything such as a 'C# var usage' Best Practice rul e out there?









The C# var keyword was introduced in C# version 3.0. According to Eric Lippert from the Microsoft C# team it was included for 2 primary reasons:and write is as--Now, much of the code you see floating around on the Internet coming from experts use vars just about anywhere where it can be used. However, I have developed a personal preference, i.e. best practice if you will, that goes like this:Is there anything such as a 'C# var usage' Best Practice rulout there? Henry Wong, Mar 17, 2011