Defining properties can be very tedious. Suppose you have a class
1: public class UserProfile
2: {
3: private int userrId;
4: private string firstName;
5: private string lastName;
6:
7: public int UserId
8: {
9: get { return this.userId; }
10: set { this.userId = value; }
11: }
12:
13: public string FirstName
14: {
15: get { return this.firstName; }
16: set { this.firstName = value; }
17: }
18:
19: public string LastName
20: {
21: get { return this.lastName; }
22: set { this.lastName = value; }
23: }
24:
25: public UserProfile() { }
26: }
It might not look like a lot of code, but when you think about the steps you need to go through to write that small amount of code, it can add up.
- Decide on the public property name.
- Declare the appropriately named and typed backing variable.
- Implement the corresponding public property.
Fortunately, C# 3.0 provides a way to simplify this. Now, we can write the class this way:
1: public class UserProfile
2: {
3: public int UserId { get; set; }
4: public string FirstName { get; set; }
5: public string LastName { get; set; }
6:
7: public UserProfile() { }
8: }
This is certainly much more compact and requires fewer steps. When the compiler sees this class, (according to Reflector) it translates it to:
1: public class UserProfile
2: {
3: [CompilerGenerated]
4: private int k_BackingField;
5: [CompilerGenerated]
6: private string k_BackingField;
7: [CompilerGenerated]
8: private string k_BackingField;
9:
10: public int UserId
11: {
12: [CompilerGenerated]
13: get
14: {
15: return this.k_BackingField;
16: }
17: [CompilerGenerated]
18: set
19: {
20: this.k_BackingField = value;
21: }
22: }
23:
24: public string FirstName
25: {
26: [CompilerGenerated]
27: get
28: {
29: return this.k_BackingField;
30: }
31: [CompilerGenerated]
32: set
33: {
34: this.k_BackingField = value;
35: }
36: }
37:
38: public int LastName
39: {
40: [CompilerGenerated]
41: get
42: {
43: return this.k_BackingField;
44: }
45: [CompilerGenerated]
46: set
47: {
48: this.k_BackingField = value;
49: }
50: }
51:
52: public UserProfile() { }
53: }
There are a few things to look out for when using this syntax. The compiler forces you to declare properties with both a get and a set. You also don't get any kind of "safety" features, such as ensuring that you don't allow a null value to be assigned to a string property. If you want these more "advanced" features, you'll still need to define your property the "old school" way.