[Solved] sender as in C# [duplicate]

Question

The as operator attempts to convert the parameter to the requested type, returning null if the conversion/cast fails. (MSDN)

So the code you provided is checking if sender is a Rectangle object (or a derived type). It then checks for null before using the converted variable, which is always good practice when using as.

Note that the second code just assigns to a different variable name, though using a class name as a variable name is strongly discouraged.

Accepted Answer

The as operator attempts to convert the parameter to the requested type, returning null if the conversion/cast fails. (MSDN)

So the code you provided is checking if sender is a Rectangle object (or a derived type). It then checks for null before using the converted variable, which is always good practice when using as.

Note that the second code just assigns to a different variable name, though using a class name as a variable name is strongly discouraged.