value (C# Reference)

The contextual keyword value is used in the set accessor in property and indexer declarations. It is similar to an input parameter of a method. The word value references the value that client code is attempting to assign to the property or indexer. In the following example, MyDerivedClass has a property called Name that uses the value parameter to assign a new string to the backing field name. From the point of view of client code, the operation is written as a simple assignment.

class MyBaseClass
{
    // virtual auto-implemented property. Overrides can only
    // provide specialized behavior if they implement get and set accessors.
    public virtual string Name { get; set; }

    // ordinary virtual property with backing field
    private int _num;
    public virtual int Number
    {
        get { return _num; }
        set { _num = value; }
    }
}

class MyDerivedClass : MyBaseClass
{
    private string _name;

    // Override auto-implemented property with ordinary property
    // to provide specialized accessor behavior.
    public override string Name
    {
        get
        {
            return _name;
        }
        set
        {
            if (!string.IsNullOrEmpty(value))
            {
                _name = value;
            }
            else
            {
                _name = "Unknown";
            }
        }
    }
}

For more information, see the Properties and Indexers articles.

C# language specification

For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.

See also