Introduction
There are two main concrete ways of encapsulating data and
behavior in the common type system of the .NET Framework: classes and structs.
Each one offers benefits over the other, and in this article I am going to briefly
introduce these two concepts and discuss how to use each and when to use each
based on their differences.
Each of these defines a schema for an object that we can
create encapsulating the data and behavior that we want into these objects that
we can create at runtime. We are able to create these objects and use them in
our code freely at runtime. We can sometimes change the values, use them, pass
them around. In object oriented programming, classes and structs are an
integral piece of the programming paradigm.
Classes
Classes are the most commonly used of these two forms of
encapsulation. The main difference between the two is that classes are a reference
type, which means that by default they're used by reference instead of by
value.
Structs
Structs are the lesser used of these two forms of
encapsulation. The primary distinction of structs is that a struct is a value
type, which means that it is stored on the stack instead of the heap and it
is passed by value instead of by reference by default.
Structs are behave similarly to the other value types that
we see when writing .NET code. These include: integers, doubles, bools, and
other value type objects.
Structs don't require constructors, but if there is one,
they require that there are parameters in the constructor.
Structs do not require the use of the new keyword in
creation, but if you use this syntax you need to initialize the members
manually.
Structs do not have access to inheritance.
When to Use Each
Classes are generally used for complex data with lots of
behavior as well as for objects which may become large. One major reason for
this is that classes never need to be copied when passing them around this
means that the same object gets reused and we don't have to be concerned with
duplicating such a large object.
Structs are generally used in situations where we need
light, quick objects which are not often changed and are used in context. They
are less often used when there will be a large amount of behavior associated
with the objects.
One great benefit of structs is the avoidance of allocating
to the heap and thus the overhead of garbage collection is avoided, but be
mindful of doing this with large objects as passing them to methods will
require copying them since they are value types.
Passing data to and from programs running in c or c++ is one
instance where structs are used instead of classes. These are the objects able
to do this work for us.
Conclusion
Structs and classes are both great ways of managing code and
each have their benefits and drawbacks. Try each one and see how well they work
in your code. Experiment with structs as value types and classes as reference
types. Try passing them into methods and then change them in the method and
notice the difference. Structs don't have side effects from this.
