Keywords

Keywords are the standard identifiers that have standard,predefined meaning in c.these key word can be used only for their intended purpose and thay cannot be used as programmer defined identifiers. The standard key words are :

Auto do goto signed unsigned

Break double if sizeof void

Case else int static volatile

Char enum long stuct while

Const extern register switch continue

Float return typedef default for

Short union

Data types

The c language defines five fundamental data types:

Data type	Meaning	Size(byte)	Minimal range
Char	Character	1	-128 to 127
Int	Integer	2	-32,768 to 32767
Float	Double precision real number	4	3.4e- to 3.4e+38 with 6 digits of precision
Double	single precision real number	8	1.7e-308 to 1.7e+308 with 10 digit precision
void	Valueless	0