Introduction to C language Learning (eight) typedef keyword

Key Words: typedef

usage: define a new name ( alias ) for various data types

typedef and basic data Types

typedef int Integer; Integer A= 8;

You can also alias an alias based on the

typedef Integer Myinteger; Myinteger AA = 8;

The original data type can also be used normally

typedef with the pointer

typedef Char *String; String str = "stone";

typedef with the structural body

typedefstruct person Per; // This will not bring up the struct keyword when defining struct variables.

Per p; P.name = "xyz";

Define and take aliases:

typedef struct Student//struct name Student can be omitted

{

int age;

} Stu;

void processstudent ()

{

Stu student = {+};

Student. age =+;

}

typedef and Point Structural Body the pointer

typedef struct

{

int age;

} Stu;

Stu Stu = {20};

typedef STU *S; //Pointer to struct to take alias S

s S = &stu;

typedef struct LNODE

{

int data;

struct Lnode *next;

} linklist, *slist;

int main (int argc, const char * argv[])

{

Linklist L = {1, NULL};

linklist ll = {2, NULL};

L.next = ≪

printf ("%d,", l.next->data);

SList SL = ≪

if (sl->next! = NULL)

printf ("%d,", sl->data);

return 0;

}

typedef with enum types

typedef enum

{

...

} Season;

Usage is similar to structural body

typedef with the pointers to functions

int sum (int a, int b)

{

return a + B;

}

void Main ()

{

typedef int (*P) (int a, int b);

p p = sum;

int result = (*p) (3, 5);

return 0;

｝

typedef with the #define

typedef char *string;

String s = "abc"

#define String char *;

String s = "abc"; This uses the same effect

When this is used:

String s1,s2; //With the first substitution: Char *s1, char *s2;

String S3,s4;   //With second substitution: char * S3, S4; <==> Char *s3, Char S4;

Introduction to C language Learning (eight) typedef keyword