Default values table (C# Reference)

The following table shows the default values of value types.

Value type Default value
bool false
byte 0
char '\0'
decimal 0M
double 0.0D
enum The value produced by the expression (E)0, where E is the enum identifier.
float 0.0F
int 0
long 0L
sbyte 0
short 0
struct The value produced by setting all value-type fields to their default values and all reference-type fields to null.
uint 0
ulong 0
ushort 0

Remarks

You cannot use uninitialized variables in C#. You can initialize a variable with the default value of its type. You also can use the default value of a type to specify the default value of a method's optional argument.

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

int a = default(int);

Beginning with C# 7.1, you can use the default literal to initialize a variable with the default value of its type:

int a = default;

You also can use the default constructor or the implicit default constructor to produce the default value of a value type, as the following example shows. For more information about constructors, see the Constructors article.

int a = new int();

The default value of any reference type is null. The default value of a nullable type is an instance for which the HasValue property is false and the Value property is undefined.

See also