c语言学习--typedef取别名

typedef是用来给类型去别名的

用法：  

typedef 原类型 新类型

#include<stdio.h>
#include<stdlib.h>

//typedef变量取别名



int main (void)
{
    int a = 10;
    typedef int u32; //typedef 原类型名 新类型名
    u32 b = 20;

    printf("u32 is %d \n",b);
    printf("the sizeof u32 is %d\n", sizeof(u32));
    printf("int is %d\n",a);

}

u32 is 20
the sizeof u32 is 4
int is 10

#include<stdio.h>
#include<stdlib.h>

//typedef 结构体取别名

struct stu
{
    int a;
    int b;
};

typedef struct stu ST;


int main (void)
{
  struct stu T1 = {1,2};

  printf("T1.a %d T1.b %d \n", T1.a, T1.b);

  ST T2 = {12,34}; // ST == struct stu
  printf("T2.a %d T2.b %d \n", T2.a, T2.b);


}

T1.a 1 T1.b 2
T2.a 12 T2.b 34