Why does the struct parameterless constructor have to be public C#

Erik Movsesyan

4y960C#

struct plane {
    public int first;
    public int second = 5;

    public plane() { //has to be public
        //first = 99; error, all uninitialized instance fields must be initialized
    }

    plane(int h) { //can be private
        //first = 88; error, all uninitialized instance fields must be initialized
    }

}

I am trying to understand the whole concept of struct initialization:
I am sorry but I need to ask 2 questions because I think they are very dependent on eacg other:

Why does the parameterless constructor have to be public? I assume It is because the implicit constructor is public but this reason is just not enough to explain it.
why do we HAVE to initialize all the non-static uninitialized fields? I mean we could do it later manually.

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vishal Joshi4y ago
@Erik

As there was no mention C# version replied with C# version 8.0

For your questions, you can check the below article for Struct
https://www.c-sharpcorner.com/blogs/changes-in-struct-in-c-sharp-10

Thanks
Erik Movsesyan4y ago
@Vishai

You are inherently wrong, from C# 10 or C# 11 I am not sure you can create parameterless constructor.
Update your SDK and check
Vishal Joshi4y ago
@Erik

In C# structure we can not create parameterless constructor.

And your second question afcose it is not require to initialize non-stati fileds.

please find below sample code i tried.
public static class Structures
    {
        public static void Main(string[] args)
        {
            TestStructure testStructure = new TestStructure();
            Console.WriteLine(testStructure.first);
            Console.ReadKey();
        }
    }

    struct TestStructure
    {
        public int first;// { get; set; }
        //public int second = 5;

        public TestStructure(int h)
        { //can be private
            first = h; //error, all uninitialized instance fields must be initialized
        }

    }