typedef struct的一点小结

typedef is one keyword of C lanuage.

It's used for define a new name of a data type. The data type include (int , char , and struct ...).

In the program,there can be two main use for this word. One is give a variable a lucid name.

The other is simplify some struct.

1，The simplest use of this word.

typedef long byte_4;

    give the known data type long a new lucid name.byte_4.

2, Typedef and struct.

typedef struct tagMyStruct

{

int a;

long b;

}Mystruct;

The code above include two means

1- define a new data type.

struct tagMyStruct

{

int a;

long b;

}

So keyword struct and tagMyStruct consitute the new data type. No matter about typedef, the data type is there.

We can use "struct tagMySturct" to define a new variable.But simple use tagMyStuct is wrong,because "struct" and "tagMyStruct" consitute

the new data type.

2- new name for the struct

typedef struct tagMyStruct MySturct;

So we can just MyStruct to define new variable.

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C language can use it's own ptr in it's struct.

below is right

typedef struct _tree tree;
struct _tree
{
    char data;
    tree *lchild,*rchild;
    tree *father;
};


typedef struct _tree
{
    char data;
    struct _tree *lchild,*rchild;
    struct _tree *father;
}tree;