12-10 about pointers

I. One-dimensional arrays

1?? Clear the number of elements 2?? Cannot make variable 3?? Index value =04?? The array name is the first address of the array

Two. Pointers

① type of pointer

such as int *//integer pointer

char *//String pointer

FLOAT *//floating-point pointer

Note: Pointers can only point to a block address and cannot be given a constant value.

The role of ②*

1?? Define a pointer variable

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

Cases:

int a = 10;

int *p = &a;

*p = 10;

③int a = 10;

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

* (pa++) = * (the next memory space of a)//the Next memory space is the original memory address value + 4 bytes

Pointer variable takes 8 bytes in 64-bit system

Example: char a[10] = {}

Char *pa =a; represents the first address of array A

*pa the first address of an array a

Three. Const a//CONST defines a variable a as a constant

Constant pointer: const INT*PA = &a

PA=20//Error: (Cannot change the direction pointed to by the pointer)

Pa=&b//Correct: (Can change the direction of the pointer)

Pointer constants

int *const PA = &a;

*PA = 20/correct (can change the value pointed to by the pointer)

Pa=&b//error (Can not change pointer direction)

Constant pointer to constant

const INT * Const PA = &a;

*pa = 20;

PA =&a;

Cannot add const before a sort variable

12-10 about pointers