1.结构体类型定义
    2.结构体变量定义
    3.结构体变量的初始化
    4.typedef改变类型名
    struct Test0
    {
    char a;
    int b;
    };
    struct Test0 test0 = {“a”,1};

    struct Test1
    {
    char a;
    int b;
    }test1={“a”,1};

    struct
    {
    char a;
    int b;
    }test2={“a”,1};

    typedef struct Test3
    {
    char a;
    int b;
    }Test3;
    Test3 test3 = {“a”, 1};