typedef

Keyword

Creates a new type.

The syntax for defining a new type is

typedef type-definition identifier;

This statement assigns the symbol name identifier to the data type definition type-definition. For example,

typedef unsigned char byte;
typedef char str40[41];
typedef struct {float re, im;} complex;
typedef char *byteptr;
typedef int (*fncptr)(int);

After these definition, you can declare

byte m, n;
str40 myStr;
complex z1, z2;
byteptr p;
fncptr myFunc;

with the same meaning as you declare

unsigned char m, n;
char myStr[41];
struct {float re, im;} z1, z2;
char *p;
int (*myFunc)(int);

User defined types may be used at any place where the built-in types may be used.