C structure: definition and example

C# Structure ： from C/C++ A classic that has migrated from the times . Structs are similar to classes , There are also many differences . Structure pairs as C# There is a lot of value for developers . Generally, no structure is needed , But there are aspects where structs do better than classes
What is the structure ？

The structure is class The little sister of the object . See you for the first time , There is little difference between them . They all contain collections of different types of fields , as follows

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1 public struct Flower
2 {
3 public string name;
4 protected int beautyRating;
5 private bool isVascular;
6 }
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Try the structure . As a simple data structure , You can think of a structure as a field package . Maybe you will use the structure as the data transmission object , Or maybe you want to run some logic in other places based on field values .

You can also encapsulate behaviors with structures , as follows ：

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1 public struct FlowerWithBehavior
2 {
3 string name;
4 int beautyRating;
5 bool isVascular;
6
7 public void makeBeautiful()
8 {
9 beautyRating = 10;
10 }
11 }
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up to now , The structure looks like a class , Just different keywords . That's all , But structures differ from classes in some important ways .

What makes the structure different ？

The most important difference is ： A structure is a value type , Class is a reference type . Classes are similar to structs , as follows ：

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1 public struct FlowerStruct
2 {
3 string name;
4 int beautyRating;
5 bool isVascular;
6
7 public FlowerStruct(string name, int beautyRating, bool isVascular)
8 {
9 this.name = name;
10 this.beautyRating = beautyRating;
11 this.isVascular = isVascular;
12 }
13 }
14
15 public class FlowerClass
16 {
17 public string name;
18 public int beautyRating;
19 public bool isVascular;
20
21 public FlowerClass(string name, int beautyRating, bool isVascular)
22 {
23 this.name = name;
24 this.beautyRating = beautyRating;
25 this.isVascular = isVascular;
26 }
27 }
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Although it looks similar , But classes and structs are different ：

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1 public void Test_Struct_Vs_Class_Equality()
2 {
3 FlowerStruct struct1 = new FlowerStruct(“Daisy”, 3, true);
4 FlowerStruct struct2 = new FlowerStruct(“Daisy”, 3, true);
5
6 FlowerClass class1 = new FlowerClass(“Daisy”, 3, true);
7 FlowerClass class2 = new FlowerClass(“Daisy”, 3, true);
8
9 Assert.Equal(struct1, struct2);
10 Assert.NotEqual(class1, class2);
11 }
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