The data pointers are the most direct and commonly used in C/s + +, so it is easier to understand. function pointers, which act as run-time dynamic invocations (such as callback functions CallBack function), are common and useful tools.
Let's start with a simple function pointer. (This part is of little value, purely to elicit the next section)
2 General function poin
http://blog.csdn.net/baliguan163/article/details/11720835
recommendation 34: Manage objects created by new with smart pointers We have repeatedly repeated in the previous recommendations: memory leaks are a big problem. Many techniques have been developed to address this problem, such as garbage Collection (garbage collection), smart pointer (smart pointers), and so on. Garbage collection technology has bee
One: Memory allocations for pointers and heaps
Let's start with the pointer: A pointer type, which in theory contains the address of other variables, so some books also call it: Address variable. Since the pointer is a type, it is the size of the type, on the Dahne server or on a normal PC, is 4 bytes in size, inside just stored a variable address. Regardless of the type of pointer, char *, int *, int (*), String *, float *, all of which indicate what
5. a deep understanding of C pointers: 5. pointers and stringsBasic Concepts
Strings can be allocated to different areas of memory. Pointers are usually used to support string operations. A string is a sequence of characters ending with the ASCII character NUL. The ASCII character NUL is \ 0. Strings are usually stored in arrays or memory allocated from the stack
of type int.Method Three, create a one-dimensional array, the elements in the array are pointers to other things, also known as Level two pointers. The function is an int fun (int **arr), which dynamically handles data that is not the same length for each column of the row.Note: You can do this only if you change the two-dimensional array to a pointer array that points to a vector. For example, the followi
Remember the beginning of work, a master told me that longjmp and setjmp play is not familiar, do not call themselves C language master. At that time I was doubtful, in order to let oneself to master direction, still spent a little time to learn longjmp and setjmp usage. It was later understood that it was not simply jumping and jumping, but rather a high-level exception-handling mechanism, which was indeed useful in some cases.In fact, longjmp and setjmp are not familiar with the C language mas
The concept of pointersThe pointer is the address that can be used to find the specified data.The pointer is the address, so when used, it is often simple to say that the pointer variable is a pointerA pointer variable is a variable that stores an addressint *p1;//applies a variable that opens up a piece of memory in memory, storing the dataOpens up 8 bytes, and the pointer is 8 bytes under the MacUsing pointers, you should actually say, using pointer
pointer is represented by (void *) and is therefore also known as a void pointer.int n=3, *p;void *GP;GP = n;p= (int *) GP1;The wild pointer, which is a pointer to an area of unavailable memory. The usual manipulation of such pointers will cause unpredictable errors in the program.The "Wild pointer" is not a null pointer, it is a pointer to "junk" memory. It is generally not wrong to use a null pointer because it is easy to judge with an if statement
Chapter 4 Structure and pointer
This chapter is the linked list. A single-chain table first, followed by a two-way linked list.
Summary:
A single-chain table is a data structure that uses pointers to store values. Each node in the linked list contains a field to point to the next node in the linked list.
There is an independent root pointer pointing to the 1st nodes of the linked list. A single-chain table can only be traversed in one direction.
How
Let's talk about how to study pointers and how to overcome the difficulties brought by pointers.
After writing a pointer blog, I always feel that I have not completely told you all my ideas.
First, the C ++ pointer is difficult for all programmers, and it is normal to avoid or make frequent mistakes. Your teacher will also make frequent mistakes.
Second, pointe
The return value of a function pointer is an array of pointers, where the return value of an int function pointer is an array of pointers, and an int pointer is placed in the array.#include #include voidFunintA) {printf ("fun:%d\ n", a);}voidFUN1 (void(*f) (int),intA) {f (a);}intGunintA) {printf ("gun:%d\ n", a);}intGUN1 (intAint(*f) (int) {printf ("gun1:%d\ n", a);}int(*hun (inta)) []{int(*p) [3] = (int(*)
The concept of pointers
The pointer is the address that can be used to find the specified data
Pointers are addresses, so when used, it's often easy to say pointer variables are pointers
A pointer variable is a variable that stores an address
int *p1;//applies a variable that opens up a chunk of memory in memory and stores the data
Opens up 8 bytes, and the
const* P2;/* Defines a const pointer (must be initialized because the value of the pointer itself cannot be changed) * *int* Const p3=a;/* The pointer itself and the content it points to can not be changed, so also have to initialize the * *Const int* Const p4=a;int const* Const p5=b;p1=p2=a; That's right*p1=*p2=8; Incorrect (the pointer points to content cannot be modified)*p3=5; That's rightP3=P1; Incorrect (the value of the pointer itself cannot be changed)p4=p5;//is incorrect (the pointer i
The nature of the pointer array and the pointer function is unchanged, or arrays and functions. and the array pointer and function pointer, which is the indication that this is the pointer, points to the types of arrays and functions respectively.
One
Array of pointers: the array that is used to store pointers, that is, the array elements are pointers
Char Const
internal copy does not change the P itself. Similar to the outside of the function is an int *p, inside is an int * tmpp, both inside the content is the same, that is the real address, but the address of the two itself is not the same, the changes to TMPP will not affect the p. You can do this by using pointers to pointers. int **p; In the function, the first solution to the reference, actually get the tru
These two days have been asked many times about this aspect of the problem, I have been not very understanding, and did not answer well, now to sweep their own blind. //The following are mostly reproduced, mixed with a few personal views, if inappropriate please inform. Array pointers (row pointers)define INT (*p) [n];() high priority, the first explanation is that p is a pointer to an integer one-dimensio
An array is a contiguous set of data, which can be traversed by the arithmetic operation of the pointer, which in turn points to each element of the array.Defines a pointer to an array element: int a[], *PA; PA=a[0]; or pa=a;After the above definition and assignment:*pa is a[0],* (pa+1) is a[1], ..., * (Pa+i) is a[i].A[i], * (pa+i), * (A+i), pa[i] are equivalent.//example 6-7 (1) using array names and subscripts to access array elements#include using namespacestd;intMain () {inta[Ten] = {1
The best way to understand a thing is to know its purpose.
My understanding of pointers is simply one sentence: If you change the value of a variable (including basic variables, struct, classes, pointers) when calling a function ), then you need its pointer.
Since C/C ++ always copies a parameter when calling a function, you cannot change the original content (Java references objects ). Therefore, you need
Reference: Baidu Encyclopedia | function pointer | entry.Pointer _ function, do not say. Oneself feel is so-easy. [Declaration format: ReturnType *function (arguments);]The focus is on the function pointer, and an array of function pointers that suddenly pops up; (specifically, I'm used to writing code first, then commenting; case A: The code is left, the comment is to the right.) Case B: The code is on, the comment is under. )function pointer , my im
In-depth understanding of Pointers-) differences between pointer functions and function pointers
I,
During the learning process, I found that this "pointer function" and "function pointer" are prone to errors. So today, I want to figure it out and find some information, first, the definitions between them:
1. A pointer function is a function with a pointer. A function returns a pointer of a certain type.
Ty
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