c++ 多态

最新推荐文章于 2025-12-30 06:51:55 发布

原创最新推荐文章于 2025-12-30 06:51:55 发布 · 560 阅读

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#c++ #compiler #parsing #class #binding #string

本文探讨了不同编程语言中多态的实现原理，并通过具体的C#代码示例解释了类型转换的过程及其背后的原因。文章重点分析了父类与子类间的类型转换是如何通过编译器处理以及内存中的实际表现来完成的。

i know how to handle the multi-state in every programming launguage, but i have no idea why it can do it ;

today ,i analysis this.

first ,we start with the parsing from base type;

int i = 6;

char c = i;

ok,why it can convert to the char type ;because they have the same the memory model;just put the int model coverring to the char model ,and truncating the redundent parts?actually,it is not,just the compiler did this,in memory ,i is being there;

i remember of the members of the internal structure:there are two addtional pointer to work something others is the space of the fileds;

so if we parse the type between parent; they have the same model. so it can convert;

namespace TstMultiState { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { Man m = new Man(); Person p = m; p.printf(); Person pn = new Person(); Man mn = (Man)p; mn.printf(); } } class Person { public Person() { } string a = "Person"; public void printf() { MessageBox.Show(a); } } class Man : Person { public Man() : base() { } string b = "this is a man"; public int GetMoney () { MessageBox.Show(b); return 1; } } }

when the compiler met the keyword vitual ,and then it asummes the technology of late binding,then it implement the function who belongs to the this pointer really points to in memory