D

decimal

A 16-byte precise decimal datatype.

default

A marker in a switch statement specifying the action to take when no case statements match the switchexpression.

delegate

A type for defining a method signature so that delegate instances can hold and invoke a method or list of methods that match its signature.

do

A loop statement to iterate a statement block until an expression at the end of the loop evaluates tofalse.

double

An eight-byte floating-point datatype.