Performance impact of unused "using" directives in C#
.net, c#, performance
Solution
Extra `Using` directives will not have any memory/performance impact on final application - they are nothing but compiler provided shortcuts to deal with long type names. Compiler uses these namespaces to resolve unqualified (or partly qualified) type names to correct types.
Problem
Just curious about it. Does it matter if I add multiple `using` directives at the starting of my code file which I don't use in my code. Like this. ``` using System; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; using System.IO; //using blah.. blah.. blah..; public class myClass { // Class members } ``` Does it have a bad impact on my application's memory usage? Does it have a bad impact on my application's performance? I know it is a good practice to remove them and we have short full support of .Net IDE to do so, but I am just curious to know about it.