国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Home Backend Development C++ Transform code with C++ function pointers: improve efficiency and reusability

Transform code with C++ function pointers: improve efficiency and reusability

Apr 29, 2024 pm 06:45 PM
c++ function pointer typedef Bubble Sort

Function pointer technology can improve code efficiency and reusability, specifically as follows: Improved efficiency: Using function pointers can reduce repeated code and optimize the calling process. Improve reusability: Function pointers allow the use of general functions to process different data, improving program reusability.

用 C++ 函數(shù)指針改造代碼:提升效率和可復(fù)用性

Use C function pointers to transform code: improve efficiency and reusability

Function pointers are a powerful tool. It allows passing a function as a parameter to another function. By leveraging this feature, we can transform our code to make it more efficient and reusable.

Improve efficiency

Using function pointers can reduce the amount of duplicate code. For example, we have an array of functions where each function performs a different calculation:

double calculate1(double x) { return x * x; }
double calculate2(double x) { return x * x * x; }
double calculate3(double x) { return pow(x, 4); }

Now, we want to create a function that can call any of these functions based on a given integer index. The traditional way is to use conditional statements:

double calculate(int index, double x) {
  if (index == 1) return calculate1(x);
  else if (index == 2) return calculate2(x);
  else return calculate3(x);
}

Using function pointers, we can store the array of functions in an array of pointers:

double (*calculateFuncs[])(double) = {calculate1, calculate2, calculate3};

We can then just use the index to directly call the required Function of:

double calculate(int index, double x) {
  return calculateFuncs[index](x);
}

This eliminates the need for conditional statements, significantly reducing the amount of code.

Improve reusability

Function pointers also improve reusability. For example, we can create a general sort function that sorts data based on a given comparison function:

void sort(int* arr, int size, bool (*compare)(int, int)) {
  // 排序算法
}

The comparison function specifies how two elements are sorted. This allows us to use different sorting algorithms, such as bubble sort or quick sort, without modifying the sort function itself.

Practical Case

Let us consider a practical case where we want to create a calculator that can perform different mathematical operations.

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef double (*FunctionPointer)(double);

vector<FunctionPointer> functions;

void registerFunction(FunctionPointer func) {
  functions.push_back(func);
}

double calculate(int index, double x) {
  return functions[index](x);
}

int main() {
  registerFunction(calculate1);
  registerFunction(calculate2);
  registerFunction(calculate3);

  double x;
  int index;
  cout << "Enter a number: ";
  cin >> x;
  cout << "Enter the function index (1-3): ";
  cin >> index;
  cout << "Result: " << calculate(index - 1, x) << endl;

  return 0;
}

This program allows the user to input a number and a function index, then calculates and outputs the result. By using function pointers to dynamically register and call the required functions, we improve code reusability and efficiency.

The above is the detailed content of Transform code with C++ function pointers: improve efficiency and reusability. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

What is the Standard Template Library (STL) in C  ? What is the Standard Template Library (STL) in C ? Jul 01, 2025 am 01:17 AM

C STL is a set of general template classes and functions, including core components such as containers, algorithms, and iterators. Containers such as vector, list, map, and set are used to store data. Vector supports random access, which is suitable for frequent reading; list insertion and deletion are efficient but accessed slowly; map and set are based on red and black trees, and automatic sorting is suitable for fast searches. Algorithms such as sort, find, copy, transform, and accumulate are commonly used to encapsulate them, and they act on the iterator range of the container. The iterator acts as a bridge connecting containers to algorithms, supporting traversal and accessing elements. Other components include function objects, adapters, allocators, which are used to customize logic, change behavior, and memory management. STL simplifies C

How to use cin and cout for input/output in C  ? How to use cin and cout for input/output in C ? Jul 02, 2025 am 01:10 AM

In C, cin and cout are used for console input and output. 1. Use cout to read the input, pay attention to type matching problems, and stop encountering spaces; 3. Use getline(cin, str) when reading strings containing spaces; 4. When using cin and getline, you need to clean the remaining characters in the buffer; 5. When entering incorrectly, you need to call cin.clear() and cin.ignore() to deal with exception status. Master these key points and write stable console programs.

What is inheritance in C  ? What is inheritance in C ? Jul 01, 2025 am 01:15 AM

InheritanceinC allowsaderivedclasstoinheritpropertiesandbehaviorsfromabaseclasstopromotecodereuseandreduceduplication.Forexample,classeslikeEnemyandPlayercaninheritsharedfunctionalitysuchashealthandmovementfromabaseCharacterclass.C supportssingle,m

What is function hiding in C  ? What is function hiding in C ? Jul 05, 2025 am 01:44 AM

FunctionhidinginC occurswhenaderivedclassdefinesafunctionwiththesamenameasabaseclassfunction,makingthebaseversioninaccessiblethroughthederivedclass.Thishappenswhenthebasefunctionisn’tvirtualorsignaturesdon’tmatchforoverriding,andnousingdeclarationis

What is the volatile keyword in C  ? What is the volatile keyword in C ? Jul 04, 2025 am 01:09 AM

volatile tells the compiler that the value of the variable may change at any time, preventing the compiler from optimizing access. 1. Used for hardware registers, signal handlers, or shared variables between threads (but modern C recommends std::atomic). 2. Each access is directly read and write memory instead of cached to registers. 3. It does not provide atomicity or thread safety, and only ensures that the compiler does not optimize read and write. 4. Constantly, the two are sometimes used in combination to represent read-only but externally modifyable variables. 5. It cannot replace mutexes or atomic operations, and excessive use will affect performance.

How to get a stack trace in C  ? How to get a stack trace in C ? Jul 07, 2025 am 01:41 AM

There are mainly the following methods to obtain stack traces in C: 1. Use backtrace and backtrace_symbols functions on Linux platform. By including obtaining the call stack and printing symbol information, the -rdynamic parameter needs to be added when compiling; 2. Use CaptureStackBackTrace function on Windows platform, and you need to link DbgHelp.lib and rely on PDB file to parse the function name; 3. Use third-party libraries such as GoogleBreakpad or Boost.Stacktrace to cross-platform and simplify stack capture operations; 4. In exception handling, combine the above methods to automatically output stack information in catch blocks

How to call Python from C  ? How to call Python from C ? Jul 08, 2025 am 12:40 AM

To call Python code in C, you must first initialize the interpreter, and then you can achieve interaction by executing strings, files, or calling specific functions. 1. Initialize the interpreter with Py_Initialize() and close it with Py_Finalize(); 2. Execute string code or PyRun_SimpleFile with PyRun_SimpleFile; 3. Import modules through PyImport_ImportModule, get the function through PyObject_GetAttrString, construct parameters of Py_BuildValue, call the function and process return

How does std::move work in C  ? How does std::move work in C ? Jul 07, 2025 am 01:27 AM

std::move does not actually move anything, it just converts the object to an rvalue reference, telling the compiler that the object can be used for a move operation. For example, when string assignment, if the class supports moving semantics, the target object can take over the source object resource without copying. Should be used in scenarios where resources need to be transferred and performance-sensitive, such as returning local objects, inserting containers, or exchanging ownership. However, it should not be abused, because it will degenerate into a copy without a moving structure, and the original object status is not specified after the movement. Appropriate use when passing or returning an object can avoid unnecessary copies, but if the function returns a local variable, RVO optimization may already occur, adding std::move may affect the optimization. Prone to errors include misuse on objects that still need to be used, unnecessary movements, and non-movable types

See all articles