Default values of C# types (C# reference)

The following table shows the default values of C# types:

Type	Default value
Any reference type	null
Any built-in integral numeric type	0 (zero)
Any built-in floating-point numeric type	0 (zero)
bool	false
char	'\0' (U+0000)
enum	The value produced by the expression (E)0, where E is the enum identifier.
struct	The value produced by setting all value-type fields to their default values and all reference-type fields to null.
Any nullable value type	An instance for which the HasValue property is false and the Value property is undefined. That default value is also known as the null value of a nullable value type.

The C# language reference documents the most recently released version of the C# language. It also contains initial documentation for features in public previews for the upcoming language release.

The documentation identifies any feature first introduced in the last three versions of the language or in current public previews.

Tip

To find when a feature was first introduced in C#, consult the article on the C# language version history.

Default value expressions

Use the default operator to produce the default value of a type, as the following example shows:

int a = default(int);

You can use the default literal to initialize a variable with the default value of its type:

int a = default;

Parameterless constructor of a value type

For a value type, the implicit parameterless constructor also produces the default value of the type, as the following example shows:

var n = new System.Numerics.Complex();
Console.WriteLine(n);  // output: (0, 0)

At runtime, if the System.Type instance represents a value type, you can use the Activator.CreateInstance(Type) method to call the parameterless constructor and get the default value of the type.

Note

A structure type (which is a value type) can have an explicit parameterless constructor that returns a non-default value of the type. To get the default value of a type, use the default operator or the default literal.

C# language specification

For more information, see the following sections of the C# language specification:

• Default values
• Default constructors
• Parameterless struct constructors
• Auto default structs

See also

• Constructors