Structs

A struct in C# is similar to a class, but it is intended for smaller data structures. A struct is a value type, whereas a class is a reference type. Each struct object contains its own copy of the data, whereas a class object contains only a reference to the data. For more information, see Value Types (C# Reference) and Reference Types (C# Reference).

All struct types inherit from the Object class, which is a root class in C#. You cannot inherit from a struct, although a struct can implement interfaces.

A struct typically can be created faster than a class. If in your application new data structures are being created in large numbers, you should consider using a struct instead of a class. Structs are also used to encapsulate groups of data fields such as the coordinates of a point on a grid, or the dimensions of a rectangle. For more information, see Classes.

Example

The following example defines a struct to store a geographic location. It also overrides the ToString() method of the Object class to produce a more useful output when displayed in the WriteLine statement.

struct GeographicLocation
{
    private double longitude;
    private double latitude;

    public GeographicLocation(double longitude, double latitude)
    {
        this.longitude = longitude;
        this.latitude = latitude;
    }

    public override string ToString()
    {
        return System.String.Format("Longitude: {0} degrees, Latitude: {1} degrees", longitude, latitude);
    }
}

class Program
{
    static void Main()
    {
        GeographicLocation Seattle = new GeographicLocation(123, 47);
        System.Console.WriteLine("Position: {0}", Seattle.ToString());
    }
}

Output

The output from this example looks like this:

Position: Longitude: 123 degrees, Latitude: 47 degrees

See Also

Concepts

C# Programming Guide

C# Language Primer

Classes

Reference

class (C# Reference)

struct (C# Reference)

Classes and Structs (C# Programming Guide)

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