c# - Why does vb.net allow class names to be parameter names? -

i have seen sub looked this:

private sub dosomething(byref placeholder placeholder)     'do placeholder object end sub 

i wonder why allowed. can name few languages not allowed. able have methods same return, parameters , names if 1 of them shared, other instance-level.

for example, let suppose there class named bird , there object this

dim bird = new bird("duck doggers") 

bird.fly() make sure duck doggers flies, however, bird.fly() make birds fly, if, instance ienumerable updated upon each constructor run of bird , bird.fly iterate ienumerable , call fly each item. far can see, impossible in vb.net, since fly either shared or instance-level. there possible problem (besides unclarity) if parameter name same class name instance said parameter?

i not have c# in front of me, wonder whether naming of parameter class possible there.

this common naming pattern majority of vb developers. of stems vb being case-insensitive. without being allowed name variables way, either variable, or class name have renamed "creatively" avoid conflicts, leads things hungarian notation, or other strange naming patterns. while may odd isn't used it, becomes 2nd nature vb developer. calling shared member on instance variable "passes though" shared member, in following example.

public class bird     public shared sub fly         debug.writeline("fly called shared")     end sub      public sub quack         debug.writeline("quack called instance")     end sub  end class  public class main     public sub test(bird bird)         bird.fly()         bird.fly()          bird.quack()         bird.quack()     end sub end class 

calling test results in following output.

fly called shared

fly called shared

quack called instance

quack called instance