Structure Constructor

Question

Hi
I want to know, can structure have constructor in C# ? If yes then please explain with an example anyone ?

Jignesh Trivedi · Accepted Answer

hi,
yes structure is also contain constructor.
Example:
struct mystruct
{
private int value1;
public mystruct(int myValue)
{
value1 = myValue;
}
public void display()
{
System.Console.WriteLine("value=" + value1);
}
}
class testClass
{
public static void Main()
{
mystruct t = new mystruct(333);
t.display();
}
}
hope this help.

Vulpes · Answer

Notice also that you can use constructor chaining - using :this() syntax - with structs as you can with classes.
In fact, there is one situation where you have to.
Consider, the following program which (surprisingly) doesn't compile:
using System;
public struct MyStruct {    public int X {get; set;}    public int Y {get; set;}
public MyStruct(int x, int y)    {       X = x;       Y = y;    }
static void Main()    {       MyStruct ms = new MyStruct(1,2);       Console.WriteLine(ms.X);       Console.WriteLine(ms.Y);       Console.ReadKey();    } }
However, if you change the constructor declaration to:
public MyStruct(int x, int y)  : this()
then it compiles and runs fine.
The reason is that the compiler automatically produces backing fields for the 'automatic' properties X and Y.
However, you're not allowed to access any instance members of a struct (including X and Y) until all its fields have been initialized by the constructor. The only way to do this is to chain to the struct's default parameterless constructor which sets all bytes of every field to zero.

Senthilkumar · Answer

Hi Vineet,
The structure allows to create the constructor like in class. But it will not allow to create the destructor.
But there are two differences with class constructor:
Structs cannot contain explicit parameterless constructors. Struct members are automatically initialized to their default values. A struct cannot have an initializer in the form: base (argument-list).
The syntax of the structure with constructor.
public struct MyStruct
{
int x, int y;
public MyStruct(int x, int y)
{
this.x = x;
this.y = y;
}
}
The reson for why structure can't have default constructor:
They cannot have custom default constructors They cannot be base classes to other types (i.e. they are implicitly sealed)
Constructor overloading:
At the same time struct allows to do constructor overloading like in classes.
It can't return any value.
public struct MyStruct
{
int x, int y;
public MyStruct(int x, int y)
{
this.x = x;
this.y = y;
}
public MyStruct(int x)
{
this.x = x;
}
}
For more info:
http://msdn.microsoft.com/en-us/library/ah19swz4(v=vs.71).aspx