OC typedef(起别名)

// #define Integer int
// 给基本数据类型起别名
void test() {
    typedef int Integer;

    typedef Integer MyInteger;

    typedef unsigned int UInteger;

    int a = ;

    Integer b = ;

    UInteger c = ;

    MyInteger d = ;
}

// 给指针类型起别名
void test1() {
    char *s = "itcast";

    typedef char * String;

    String s1 = "itcast";
}

void test2() {
//    struct MyPoint {
//        float x;
//        float y;
//    };
//    struct MyPoint p = {10, 10};

    typedef struct {
        float x;
        float y;
    } Point;

    Point p = {, };
}

void test3() {
    typedef struct {
        float x;
        float y;
    } Point;

    typedef Point * PP;

//    typedef struct Point {
//        float x;
//        float y;
//    } * PP;

    Point point = {10.0f, 20.0f};

    PP pp = &point;

    printf("x=%f, y=%f\n", pp->x, pp->y);
}

void test4() {
    typedef enum {
        spring,
        summer,
        autumn,
        winter
    } Season;

    Season s = spring;
}

int sum(int a, int b) {
    int c = a + b;
    printf("%d+%d=%d\n", a, b, c);
    return c;
}

// 给指向函数的指针定义一个别名SumPoint
void test5() {
    typedef int (*SumPoint)(int, int);

    SumPoint p = sum;

    (*p)(, );
}

void test6() {
    typedef char * String1;
    #define String2 char *

    String1 s1,s2;
//    String1 s1;
//    String1 s2;

    String2 s3,s4;
//    char *s3, s4;
//    char *s3;
//    char s4;
}

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

    int a, b;

//    int a;
//    int b;

    return ;
}