* and & symbols in C language

int a = 10;
int *b = &a;
printf(“%d\n”, a);
printf(“%d\n”, &a);
printf(“%d\n”, b);
printf(“%d\n”, *b);

result

10
6487620
6487620
10

Variable a Essentially represents a storage unit CPU The data in the storage unit is accessed through the address of the storage unit . therefore a Originally represents two values ： The address of the storage unit and the data in the storage unit . So there is the opposite sex . To eliminate this ambiguity ,C Language policy a Represents the data in the storage unit ,&a Indicates the address of the storage unit .
a The data in the storage unit can be an ordinary value , It can also be the address of another storage unit , such as ：a = &b; The statement is to b The address of the storage unit is stored in a In the storage unit .C Language policy a representative a Data in the storage unit corresponding to the address stored in , That is to visit a Equal to access b, therefore *a Provided through a visit b Means of data in .

a Express a Data in the corresponding storage unit .
&a Express a Address of the corresponding storage unit .

a Express ： First , requirement a The data in the corresponding storage unit must be the address of another storage unit .
therefore ,a Represents data in another storage unit .
When a The type of declaration is int when ,a Stored in is an integer value , adopt a You can visit （ To read or modify ） The numerical .
When a The type of declaration is int when ,a Stored in is the address of a storage unit , The data stored in the storage unit is an integer value ; adopt a You can visit （ To read or modify ） The numerical .a == &*a Are the address of the storage unit .
When a The type of declaration is int** when ,a Stored in is the address of a storage unit , The data stored in this storage unit is the address of another storage unit , In addition, this storage unit stores an integer value ; adopt **a You can visit （ To read or modify ） The numerical .

Last , stay C In language, address is called pointer . also , stay C Arrays in language are actually pointers , namely ：*a Equate to a[].