C Language Pointers

1. The pointer is the same type as int char float, called the pointer type, denoted by *

2, pointer variable, pointer variable is what type of pointer, depends on what type of variable it points to

Integer pointer int *

String char *

Floating-point Pointer float *

3, note: The pointer can only point to a block address, cannot point to a constant value

For example int *p = 10; This is wrong.

& means take address, &a

so int *p = &a;

4. The pointer variable is 8 bytes in memory (64-bit operating system)

5. The function of the * number

1. Define a pointer variable

2.* (pointer variable) = = Gets the value of the variable pointed to by the pointer

For example int a = 10;

int *p = &a;

*p = 10;

(*p) + + =a++ = 11;

* (p++) = * (Next memory space of P) = the value in the next training space of P is treated as an address, and the corresponding value of this address is obtained.

6. Constant pointer

const int *PA = &a;

*pa = 20; Cannot change the value of the variable pointed to

PA = &b; can change pointer pointing

7. Pointer constant

int *const PA = &a;

*pa = 20; You can change the value of the variable pointed to by the pointer

PA = &b; cannot change pointer pointing

8. Constant pointer to constant

const int *const PA = &a;

*pa = 20;

PA = &b;

C Language Pointers