typedef用于定义一种新类型
例如
定义了如下的结构
typedef struct student
{
int age;
int score;
}STUDENT;
那么则有
STUDENT stu1;
就相当于struct student stu1;
上面的结构也可以直接定义为:
typedef struct
{
int age;
int score;
}STUDENT;
然后将STUDENT作为新类型使用,比如STUDENT stu1;
typedef声明新的类型来代替已有的类型的名字。
如:
typedef int INTEGER;
下面两行等价
int i;
INTEGER i;
可以声明结构体类型:
typedef struct
{
int age;
int score;
}STUDENT;
定义变量:
只能写成 STUDENT stu;
如果写成
typedef struct student
{
int age;
int score;
}STUDENT;
下面三行等价:
STUDENT stu;
struct student stu;
student stu;
 #include <stdio.h>
#include <ctype.h>
#include <conio.h> void main()
{
char letter; // Letter typed by the user printf("Do you want to continue? (Y/N): "); letter = getch(); // Get the letter
letter = toupper(letter); // Convert letter to uppercase while ((letter != 'Y') && (letter != 'N'))
{
putch(); // Beep the speaker
letter = getch(); // Get the letter
letter = toupper(letter); // Convert letter to uppercase
} printf("\nYour response was %c\n", letter);
}
 
04-13 14:08