This article mainly introduces the C language of constant pointer and pointer constant difference, the need for friends can refer to
A constant pointer refers to a pointer to a constant, as the name suggests, is the pointer to a constant, that is, it can not point to the va
In this paper, some techniques for understanding C + + pointer arrays, array pointers, array names, and two-dimensional arrays are analyzed in detail. is a more important concept, I believe that for everyone's C + + program design has a certain role in helping.
First, about the array name
Suppose you have an array:
int a[3] = {1, 2, 3}
1. The array name represents the address of the first element of the array , noting that not the arra
A constant pointer to an object
Declare the pointer variable to the object as a const and initialize it so that the pointer value remains at its initial value and cannot be changed.
Copy Code code as follows:
Time T1 (10,12,15), T2;
Time * Const ptr1=t1;
ptr1=t2;
The general form of a constant point
1. Pointer addition and subtraction operations1) pointer + integer will move backward sizeof (pointer type) * Whole number of memory units2) pointer-integer will move forward sizeof (pointer type) * Whole number of memory units3) Description: The compiler will not check whet
C language pointer learning, C language pointer
I have learned C language for a long time, but I don't have a very clear understanding of the pointers in it. I have the opportunity to study it well and summarize the learned knowledge. The knowledge comes from the explanation of C language pointers.I. pointer Concept
A pointer
Reprint: http://blog.csdn.net/u012434102/article/details/44886339
When you write data structures with C + +, the link list and two-fork tree often need to use a two-level pointer or a pointer to a reference, then when to use when not.First look at a simple C + + list operating procedures:
#include "stdio.h" #include "stdlib.h" #include "time.h" #define OK 1 #define ERROR 0 #define TRUE 1 #define FALSE 0 #
Interpretation of the concept of C ++ pointer and pointer
Interpretation of the concept of C ++ pointerUltra-detailed
A pointer is a special variable. The value stored in it is interpreted as an address in the memory. To understand a pointer, we need to understand four aspects of the
First, take a look at a small example of an array of pointers:
#include
Array pointers:
#include
The two names are different, of course, the meaning is different. I just started to see this scare, mainly Chinese is too broad and profound, the whole of this abbreviation is too professional, the people are around dizzy. It is easier to understand from the English explanation or the Chinese full name.
Array of pointers: array of pointers, which is used to store pointe
Nullptr
A null pointer is a pointer that does not point to valid data, previously expressed in 0, but this makes 0 both a pointer constant and an integer constant. C++11 still allows 0来 to represent a null pointer, so the expression nullptr==0 true, and using nullptr to represent a null
6.3.1 pointer operators and pointer expressions
There are two operators on pointers in C:
Operator: Takes the address operator, m is the address of the variable m.
* Operator: pointer operator, *PTR represents the variable to which it is pointing.
[Example 6-2] Enter two integers from the keyboard and output in order from large to small.
main() { int *p1,*p
Preface
Today, the error caused by the misuse of the pointer in the drive development: Unable to handle kernel NULL pointer dereference in virtual address xxxxxxxx. This error is what I encountered when I used DMA for the LCD driver, and the error caused by referencing an empty pointer when allocating the memory used for the DMA transfer. The error printing info
Constant pointer:const int* x indicates that the x being referred to is a constant and the pointer itself is a variable. If the pointer points to a constant, you must use a constant pointer
Pointer constant: int* const y indicates that the pointer itself is a constant, and
1
5
9
Summarized as follows:
???
Pis a level two pointer???
P? is the address of the cell that holds this level two pointer?: 0012ff40???
PThe value is: 0012ff44??? *
P? is
P
Tidy up the room, turn out a piece of stationery, think of the previous reading notes. As follows:typedef double (* fun-ptr) (int);Fun-ptr A pointer to a function that has an int parameter and returns a double. Analogy Imagination: Double fun-name (int a);Row pointer: double (* data) [5];Data is a pointer to an array that contains 5 double. Analogy imagination: D
1, the mouse right click Computer Desktop, in the menu select "Personalized."
2, in the "Control Panel personalization window" in the mouse click on the left-hand side of the "Change the mouse pointer" link text, as shown in the following figure.
3, in the mouse properties of the custom select "Normal Selection", and then click "Browse", select the corresponding icon, and so on double-click "Help select" Select the corresponding icon,
each () Definition and usage
The each () function generates an array of key names and key values of the elements that the array's current internal pointer points to, and moves the internal pointer forward.
The four elements included in the returned array: The key name is 0,1,key and value. The unit 0 and key contain the key names of the array cells, and 1 and value contain the data.
If the internal
#include #./aaa-----a[10]----a size:10, pa size;8, *pa size:1, *paa size:10When the first address of a character array is coerced into a char * pointer: sizeof (*PTR) is not the size of the array;C: When the first pointer of a character array is converted to a char * pointer, sizeof (*PTR) is not an array of size
Problem thinking:In a two-dimensional array, you cannot use the array name to express the first element of the array. The matrix no longer represents the address of the first element of the array.Array type:int array[5] is of type int[5], not int. INT[5] shows that this array has 5 elements, each element type is int.To define an array type:Array pointers:Examples of array types and arrays of pointers:1#include 2 3typedefint(AINT5) [5];4typedeffloat(AFLOAT10) [Ten];5typedefChar(ACHAR9) [9];6 7 in
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.