The problem of structs in the C language, the understanding of constructs in the C language

It seems that you don't know much about structs and struct pointers, the data array is a struct array that you define, it consists of two knot body elements, and each struct element contains two members x and y, the first element is 1 and 10, the second element is 2 and 20, the struct pointer p you defined starts to point to the first element of the array data, p points to the second element of the data array, and the pointer p can manipulate the two members x and y

In the beginning: p->x is 1

p->y is 10

p pointer plus 1 to move to the second element of the array:

p->x is 2

P->y is 20

Do you understand?

p=data, where p points to 1

p->y points to the next one of 1, i.e. 10

p->x points to 2 after p-x

p->y after p points to 20

That is true. struct st *p=data;First, assign the first address of the array to p;

But p is of type struct and has two integer variables, so p thinks that the two integer variables 1 and 10 belong to it, so the value of p->y is 10

In the second statement, it should be clear that p++ is the number of bytes occupied by the type of struct st, first of all, st is a struct type with two int variables, so after ++p, the point of p must be moved back by the size of the number of two int types, where p points to 2, so (++p)->x is equal to 2

If you still don't feel detailed enough and not clear enough, you can send me a message.

Define the struct variable st, and define the struct variable array data;

struct st

int x,y;

data[2]=;

main()

struct st *p=data;A pointer that defines a struct variable, pointing to an array.

printf("%d",p->y);

printf("%d",(+p)->x);(++p) points to the second struct element of the array.

It can be understood that there are two elements in the array data.

The defined pointer p is structural, so ++p is already pointing.

struct st

int x,y;} data[2]=;means data[0]=, i.e. data[0].x=1,data[.y=10.

So *p=data[0]. p->y = 10;

When you increment pointer p by 1, the pointer moves to data[1] (not to 10). Each move is a move of the whole. So (++p)->x=2.

1. Definition of structureA struct is a collection of one or more pieces of data, which can be of different types, and the struct is equivalent toarrayupgrades. If we want to count the grades of students in a class, and the grades are of the float type, we can use the gradesarrayDeposit. However, if you want to count the name, gender, and grades of students in a class, the name is a string, the age is an integer, and the grade is a decimal, because the data type is different, it obviously cannot be usedarrayDeposit.

To solve this problem, another type of construct data is given in C - struct. It can store multiple data types of the same object together.

2. Definition formWay 1, place the struct variable directly at the tail end of the struct.

struct structure name; Zhang San male scored 100Fourth, the use of structureTake the example of Mode 2 as an example.

struct student ；Zhang San Male Score 100*** Use***

zhangsan. score =60；Assign Zhang San's score to 60