How to initialize struct

Question

What member should I implement in my arbitrary structure to make the following assignment possible   public struct MyStruct      String s     Int length     MyStruct myStruct   new MyStruct   s    Hello   length   5        Now  I want the following code to set the  s  to  Lol  and the    length to 3  length of  Lol    The second part should be done    automatically  myStruct    Lol      Or myStruct   String  Lol      How should this be done

User · Answer

Your struct can have methods and properties... why not try

public struct MyStruct { 
    public string s;
    public int length { return s.Length; }
}

Correction @Guffa's answer shows that it is possible... more info here: http://www.codeproject.com/KB/cs/Csharp_implicit_operator.aspx

User · Answer

Will  length  ever deviate from the real length of  s   If the answer is no  then you don t need to store length  because strings store their length already  and you can just call s Length  To get the syntax you asked for  you can implement an  implicit  operator like so   static implicit operator MyStruct string s        return new MyStruct          The implicit operator will work  regardless of whether you make your struct mutable or not

User · Answer

You use an implicit operator that converts the string value to a struct value   public struct MyStruct     public string s    public int length     public static implicit operator MyStruct string value        return new MyStruct     s   value  length   value Length             Example   MyStruct myStruct    Lol   Console WriteLine myStruct s   Console WriteLine myStruct length     Output   Lol 3

User · Answer

Structure types should  whenever practical  either have all of their state encapsulated in public fields which may independently be set to any values which are valid for their respective type  or else behave as a single unified value which can only bet set via constructor  factory  method  or else by passing an instance of the struct as an explicit ref parameter to one of its public methods   Contrary to what some people claim  that there s nothing wrong with a struct having public fields  if it is supposed to represent a set of values which may sensibly be either manipulated individually or passed around as a group  e g  the coordinates of a point    Historically  there have been problems with structures that had public property setters  and a desire to avoid public fields  implying that setters should be used instead  has led some people to suggest that mutable structures should be avoided altogether  but fields do not have the problems that properties had   Indeed  an exposed-field struct is the ideal representation for a loose collection of independent variables  since it is just a loose collection of variables   In your particular example  however  it appears that the two fields of your struct are probably not supposed to be independent   There are three ways your struct could sensibly be designed    You could have the only public field be the string  and then have a read-only  helper  property called length which would report its length if the string is non-null  or return zero if the string is null  You could have the struct not expose any public fields  property setters  or mutating methods  and have the contents of the only field--a private string--be specified in the object s constructor   As above  length would be a property that would report the length of the stored string  You could have the struct not expose any public fields  property setters  or mutating methods  and have two private fields  one for the string and one for the length  both of which would be set in a constructor that takes a string  stores it  measures its length  and stores that   Determining the length of a string is sufficiently fast that it probably wouldn t be worthwhile to compute and cache it  but it might be useful to have a structure that combined a string and its GetHashCode value    It s important to be aware of a detail with regard to the third design  however  if non-threadsafe code causes one instance of the structure to be read while another thread is writing to it  that may cause the accidental creation of a struct instance whose field values are inconsistent   The resulting behaviors may be a little different from those that occur when classes are used in non-threadsafe fashion   Any code having anything to do with security must be careful not to assume that structure fields will be in a consistent state  since malicious code--even in a  full trust  enviroment--can easily generate structs whose state is inconsistent if that s what it wants to do   PS -- If you wish to allow your structure to be initialized using an assignment from a string  I would suggest using an implicit conversion operator and making Length be a read-only property that returns the length of the underlying string if non-null  or zero if the string is null

[c#] How to initialize struct?

Examples related to c#

Examples related to struct

Examples related to initialization