C + + learning (1)

C + + learning (1)

1.const C VS C + +:

In the C language , const is a read-only variable (ReadOnly varible), and in C + + Const represents only constants (Constant ).

Cases:

const int n=10;

int Arry[10]//ok in C + + error in C.

2. Two properties of the pointer:

(1). The pointer itself;

(2). The data that the pointer points to;

3. constant pointer and pointer constants:

(1). constant Pointer (point toconstant or constantpoint):

Concept: A pointer to a constant;

Definition:const int* p;

Cases:

const int * p1;

const int x=1;

p1=&x;// Correct

*p1=10;// Error

Here constant refers to the solution reference is a constant;

(2). pointer constant (pointconstant)

Concept: The immutable pointer points to a variable value;

Definition:int* const p;

Cases:

const INT X=1

int* Const p1=&x;// A super important step, be sure to write on P1 who to point to

*p1 = x//or y, also can not write, do not write the words represent the value of the variable that P1 points to;

p1=&y// is wrong because the pointer is not variable in the pointer constant

# The array name is a pointer constant!!

C + + learning (1)