11.1.1 Default constructors

11.1.1 Default constructors

All value types implicitly declare a public parameterless instance

constructor called the default constructor.

The default constructor returns a zero-initialized instance known as the

default value for the value type:

?For all simple-types, the default value is the value produced by a bit

pattern of all zeros:

For sbyte, byte, short, ushort, int, uint, long, and ulong, the default

value is 0.

For char, the default value is 抃x0000?

For float, the default value is 0.0f.

For double, the default value is 0.0d.

For decimal, the default value is 0.0m.

For bool, the default value is false.

?For an enum-type E, the default value is 0.

?For a struct-type, the default value is the value produced by setting all

value type fields to their default

value and all reference type fields to null.

Like any other instance constructor, the default constructor of a value

type is invoked using the new

operator. [Note: For efficiency reasons, this requirement is not intended

to actually have the implementation

generate a constructor call. end note] [Example: In the example below,

variables i and j are both initialized

to zero.

class A

{

void F() {

int i = 0;

int j = new int();

}

}

end example]

Because every value type implicitly has a public parameterless instance

constructor, it is not possible for a

struct type to contain an explicit declaration of a parameterless

constructor. A struct type is however

permitted to declare parameterized instance constructors (?8.3.8).