Backend Development
C++
The relationship between C++ function parameter passing methods and class inheritance
The relationship between C++ function parameter passing methods and class inheritance
Apr 12, 2024 am 11:06 AM
Question: What is the relationship between C function parameter passing methods and class inheritance? Answer: When a subclass inherits a parent class function, the parameter passing method can be the same or different. If the subclass does not override the parent class function, it inherits the parent class's parameter passing method. If a subclass overrides a parent class function, it can choose to use a different parameter passing method. When a subclass needs to modify parameters in a parent class function, it needs to declare the parent class function as pass-by-reference.
C The relationship between function parameter passing method and class inheritance
Introduction
There are two ways to pass function parameters in C: pass by value and pass by reference. When a parent class function is overridden by a child class, the parameter passing method may be affected. This article will explore the relationship between function parameter passing methods and class inheritance.
Pass by value
Pass by value makes a copy of the parameters when the function is called, so that modifications to the parameters within the function will not affect the actual parameters in the calling function.
void swap(int a, int b) {
int temp = a;
a = b;
b = temp;
}
int main() {
int x = 1, y = 2;
swap(x, y); // x 和 y 的值不會(huì)改變
return 0;
}Pass by reference
Pass by reference directly uses the address of the parameter storage when the function is called, allowing the function to directly modify the actual parameters in the calling function.
void swap(int& a, int& b) {
int temp = a;
a = b;
b = temp;
}
int main() {
int x = 1, y = 2;
swap(x, y); // x 和 y 的值被交換
return 0;
}Class inheritance and parameter passing
When a subclass inherits a parent class function, the parameter passing method of the subclass function can be the same or different from the parent class function.
Example of unchanged parameter passing method
If the subclass function does not override the parent class function, the subclass function will inherit the parameter passing method of the parent class function.
class Base {
public:
void func(int a);
};
class Derived: public Base {
public:
using Base::func; // 不覆蓋 func，繼承按值傳遞
};Example of changing parameter passing method
If a subclass function overrides a parent class function, the subclass function can choose to use a different parameter passing method.
class Base {
public:
void func(int a) {}
};
class Derived: public Base {
public:
void func(int& a) {} // 覆蓋 func，使用按引用傳遞
};Practical case
Consider a Shape base class with a print() function and an inheritance Shape and a Circle subclass with the draw() function. If Shape::print() passes a Shape reference by value, Circle::draw() will not be able to modify the parent class's print( ).
class Shape {
public:
virtual void print(const Shape& shape) {}
};
class Circle: public Shape {
public:
void draw() {
// 無(wú)法修改父類(lèi)的 print()
print(static_cast<Circle&>(*this));
}
};In order to allow subclasses to modify the parent class's print(), print() needs to be declared as pass-by-reference.
class Shape {
public:
virtual void print(Shape& shape) {}
};
class Circle: public Shape {
public:
void draw() {
// 可以修改父類(lèi)的 print()
print(*this);
}
};The above is the detailed content of The relationship between C++ function parameter passing methods and class inheritance. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
C tutorial for people who know Python
Jul 01, 2025 am 01:11 AM
People who study Python transfer to C The most direct confusion is: Why can't you write like Python? Because C, although the syntax is more complex, provides underlying control capabilities and performance advantages. 1. In terms of syntax structure, C uses curly braces {} instead of indentation to organize code blocks, and variable types must be explicitly declared; 2. In terms of type system and memory management, C does not have an automatic garbage collection mechanism, and needs to manually manage memory and pay attention to releasing resources. RAII technology can assist resource management; 3. In functions and class definitions, C needs to explicitly access modifiers, constructors and destructors, and supports advanced functions such as operator overloading; 4. In terms of standard libraries, STL provides powerful containers and algorithms, but needs to adapt to generic programming ideas; 5
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 ?
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 ?
Jul 01, 2025 am 01:15 AM
InheritanceinC allowsaderivedclasstoinheritpropertiesandbehaviorsfromabaseclasstopromotecodereuseandreduceduplication.Forexample,classeslikeEnemyandPlayercaninheritsharedfunctionalitysuchashealthandmovementfromabaseCharacterclass.C supportssingle,m
What is function hiding in C ?
Jul 05, 2025 am 01:44 AM
FunctionhidinginC occurswhenaderivedclassdefinesafunctionwiththesamenameasabaseclassfunction,makingthebaseversioninaccessiblethroughthederivedclass.Thishappenswhenthebasefunctionisn’tvirtualorsignaturesdon’tmatchforoverriding,andnousingdeclarationis
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
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 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
