C language pointer, C language pointer

C language pointer, C language pointer

Pointers are very important data types in C language. What are pointers?

The pointer type is a variable used to store the variable address, pointing to a variable.

Common pointer format: * pointer variable name

Int * p;

Float * p1;

"*" Is used to indicate that this variable is a pointer variable. The previous type identifier indicates the type pointing to the variable.

// Define an integer variable a and initialize it to 10

Int a = 10;

// Define a pointer Variable p that can point to the int address

Int * p;

// Assign the address of variable a to the pointer Variable p, so the pointer Variable p points to variable
P = & a; // you can obtain the address of a variable in the memory.

Error instance:

Int * g;

G = 20;

Generally, the value of a pointer variable cannot be directly assigned an integer, but is assigned by the variable address, as shown below:

* P = 20;

Printf ("a = % d \ n", );

Void * p3; // This is called a non-type pointer, which means this is only a pointer variable and does not point to any specific data type, however, you can convert void * to another type pointer by force conversion, or convert other types of pointer to void type pointer by using (void *).

NULL Pointer: the pointer value is NULL.