Menu
Can anyone clearly articulate when you use a field and when to use a property in class design?
Consider:
public string Name;
Or:
private string _Name;
public string Name
{
get { return _Name; }
set { _Name = value; }
}
I realize that the second method is more proper and flexible, so that's what I try to use, generally.
But then why do I see people use the first method? Are they just lazy, or is there some specific situation where it's the correct choice? Is it just a matter of preference?
827
A field is a variable of any type that is declared directly in a class. A property is a member that provides a flexible mechanism to read, write or compute the value of a private field. A field can be used to explain the characteristics of an object or a class.
Properties can be used to read only or write only other fields. This could be done by declaring only either get{} or set{}. Also they can have access modifiers, like private, so you can only get or set their values inside their class.
Properties have the primary advantage of allowing you to change the way data on an object is accessed without breaking it's public interface. For example, if you need to add extra validation, or to change a stored field into a calculated you can do so easily if you initially exposed the field as a property.
When should I use a property? In general, you should use properties if you need them to look and behave like a variable. Properties give you a level of abstraction to change the fields while not affecting how a class uses them.
Well in C# 3.0 you can actually write:
public string Name {get; set;}
Which allows you to be proper and lazy.
Generally speaking, with properties, you get proper encapsulation. You have the choice to allow setting a value, or getting it, or both. Using a public member, you don't have that option.
It's probably one-part preference, and one-part how your team decides to handle quick and dirty class definitions, but I would say, use properties for get/sets.
To answer
Can anyone clearly articulate when you use an attribute and when to use a property in class design?
You shouldn't ever use a public attribute. You should always use a property instead. It's safer and more flexible. That said, people will be lazy, and just use a public member. However, with C# 3.0 you can use a more terse syntax to define properties, which should satisfy your inner laziness.
Simply type prop and hit <tab> to expedite the laziness in adding a property.
181
Just some additional information to Alan's reply:
public string Name {get; set;}
is the same as
private string _Name;
public string Name{
get { return _Name; }
set { _Name = value; }
}
If you want to disallow the set function of Name, you can have
public string Name {get; private set;}
45
Properties are more maintainable than fields, you can encapsulate logic in your setters/getters, allowing you to hide the implementation.
They also make refactoring easier.
More information:
42
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
