Thenew constraint specifies that a type argument in a generic class or method declaration must have a public parameterless constructor. To use thenew constraint, the type cannot be abstract.

Apply thenew constraint to a type parameter when a generic class creates new instances of the type, as shown in the following example:

class ItemFactory<T> where T : new(){    public T GetNewItem()    {        return new T();    }}

When you use thenew() constraint with other constraints, it must be specified last:

public class ItemFactory2<T>    where T : IComparable, new(){  }

For more information, seeConstraints on Type Parameters.

You can also use thenew keyword tocreate an instance of a type or as amember declaration modifier.

C# language specification

For more information, see theType parameter constraints section of theC# language specification.

See also

• C# Keywords
• Generics