Keywords acquaintance C language

C89 standard defines 32 keywords

Keyword	meaning
void	Declare function does not return a value or no parameter declared null pointer type
char	Declare character variables
short	Declare short integer variable
int	Declare integer variables
long	Declare long integer variable
float	Float variable declaration
double	Declare double variables
sizeof	Computing objects share memory space size in bytes (Byte)
signed	Statement signed type variable
unsigned	Unsigned type variable declaration
struct	Declare structure variables
union	Joint Statement data types
enum	Declare enumerated types
typedef	Alias ​​to the data type
auto	Declare an automatic variable, usually when the default compiler defaults to auto
static	Declare a static variable
external	Declare variables declared in other documents that reference variables
register	Declare register variables
const	Statement read-only variable, namely the constant
volatile	Description program execution can be implicitly changed
if	Conditional statements
else	Negative branch of the conditional statement, if used in conjunction with
for	General loop
while	Loops of cycling conditions
do	Loop circulation statement
break	Out of the current cycle
goto	Unconditional jump statement
continue	End the current cycle, the next cycle start
return	Subroutine return statements can take parameters, and no arguments
switch	A switch statement
case	A switch statement branch
default	Default branch switch statement

The keyword classification (easy to remember)

Sorted	content
The type of data	void, char, short, int, long, float, double, sizeof
Whether the symbol	signed, unsigned
Constructed type	struct, union, enum, typedef
The type of storage and life cycle	auto, static, extern, register, const, volatile
Type of statement	if, else, for, while, do, switch, case, default, goto, break, continue, return