一，結構體的定義

1. 定義的同時，初始化

   1. struct Dog
          {
              char *name;
              int age;
              double height;
          };
      struct Dog sd = {"wc", 13, 5.0};

       

2. 先定義，再逐個初始化

   1. struct Dog
          {
              char *name;
              int age;
              double height;
          };
      struct Dog sd1;
      sd1.name = "ww";
      sd1.age = 5;
      sd1.height = 10.9;
       
      

       

3. 先定義，再一次性初始化

   1. struct Dog
          {
              char *name;
              int age;
              double height;
          };
      struct Dog sd2;
          // 特別注意: 結構體和陣列有一點區別, 陣列不能先定義再進行一次性的初始化, 而結構體可以
          // 只不過需要明確的告訴系統{}中是一個結構體
      sd2 = (struct Dog){"xq", 8, 8.8}; 

       

4. 指定將資料賦值給指定的屬性

   1.  struct Dog
          {
              char *name;
              int age;
              double height;
          };
      // 指定將資料賦值給指定的屬性
      struct Dog sd3 = {.height = 1.77, .name = "ww", .age = 33};
       
      

       

5. 定義結構體時，定義結構體變數

   1.   struct Dog
          {
              char *name;
              int age;
              double height;
          } sd4;
      
          sd4.age = 30;

       

6. 定義結構體型別的同時定義結構體變數, 並且省略結構體名稱

   1.   struct 
          {
              char *name;
              int age;
              double height;
          }sd5;
      sd5.age = 10;
      // 弊端: 由於結構體型別沒有名稱, 所以以後就不能使用該結構體型別
      // 優點: 如果結構體型別只需要使用一次, 那麼可以使用該方式
       
      

       

7. typeDefine定義結構體

   1.   typedef struct {
                  int year;
                  int month;
                  int day;
              } MyDate2;
              
      // 結構體型別變數為 d2，並賦值
              MyDate2 d2 = {2016, 5, 24};

       

8. 蘋果官方結構體

   1. //CGSize結構體定義
      struct CGSize {
          CGFloat width;
          CGFloat height;
      };
      typedef struct CG_BOXABLE CGSize CGSize;
      
      //CGSize設定方法結構體定義
      CG_INLINE CGSize
      CGSizeMake(CGFloat width, CGFloat height)
      {
        CGSize size; 
        size.width = width;
        size.height = height;
        return size;
      }
      
      //行內函數和巨集
      CG_INLINE：CG_INLINE is a #define for static inline. This causes the compiler to create the code for the function inline, rather that creating a function call on the stack. See here and here for more information
      
      

9. 仿照蘋果官方的自定義結構體

   1. //自定義結構體
      struct ClickSize {
          CGFloat top;
          CGFloat left;
          CGFloat bottom;
          CGFloat right;
      };
      typedef struct ClickSize ClickSize;
      
      /*
      也可以用以下方法代替上述
      typedef struct ClickSize {
          CGFloat top;
          CGFloat left;
          CGFloat bottom;
          CGFloat right;  
      
          } ClickSize;
      */
      
      //自定義結構體設定方法
      CG_INLINE ClickSize
      ClickSizeMake(CGFloat top, CGFloat left, CGFloat bottom, CGFloat right)
      {
          ClickSize clickSize;
          clickSize.top = top;
          clickSize.left = left;
          clickSize.bottom = bottom;
          clickSize.right = right;
          return clickSize;
      };
      

       

二，儲存空間

會獲取結構體型別中佔用記憶體最大的屬性的大小, 然後取該大小的倍數

三，訪問結構體變數的方法

1.       結構體變數名稱.屬性;

   1.  struct Person
          {
              int age;
              char *name;
              double height;
          };
          
          struct Person sp = {30, "ln", 1.75};
          
          sp.name = "lnj";

       

2.      (&結構體變數名稱)->屬性;

   1. struct Person
          {
              int age;
              char *name;
              double height;
          };
          
          struct Person sp = {30, "ln", 1.75};
          (&sp)->age = 20;

       

3.      (*結構體指標變數名稱).屬性;

   1.   struct Person
          {
              int age;
              char *name;
              double height;
          };
          
          struct Person sp = {30, "ln", 1.75};
          struct Person *sip;
          sip = &sp;
          (*sip).age = 88;

       

4.      結構體指標變數名稱->屬性;

   1.   struct Person
          {
              int age;
              char *name;
              double height;
          };
          
          struct Person sp = {30, "ln", 1.75};
          struct Person *sip;
          sip = &sp;
          (*sip)->age = 88;