这个问题已经在c# /. net上下文中提出过了。

现在我想学习c++中结构体和类的区别。请讨论在OO设计中选择一种或另一种的技术差异以及原因。

我将从一个明显的区别开始:

如果没有指定public:或private:,结构体的成员默认为public;默认情况下,类的成员是私有的。

我敢肯定,在c++规范的晦涩角落里还会发现其他不同之处。


当前回答

您可以将此作为何时使用struct或class的指导方针,https://msdn.microsoft.com/en-us/library/ms229017%28v=vs.110%29.aspx。

的实例,考虑定义一个结构体而不是类 类型小,通常寿命短或通常嵌入 其他对象。 避免定义结构体,除非该类型具有所有的 以下特点: 它在逻辑上代表一个值, 类似于基本类型(int, double等)。 它有一个实例 大小小于16字节。 它是不可变的。 它不必被装箱 频繁。

其他回答

struct和class之间的主要区别是,在struct中只能声明不同数据类型的数据变量,而在class中可以声明数据变量和成员函数,因此可以通过函数操作数据变量。

-> another handy thing that i find in class vs struct is that while implementing files in a program if you want to make some operations of a struct again and again on every new set of operations you need to make a separate function and you need to pass object of struct after reading it from the file so as to make some operations on it . while in class if you make a function that does some operations on the data needed everytime..its easy you just have to read object from file and call the function..

但这取决于程序员认为哪种方式合适……对我来说,我更喜欢类,因为它支持oop,这就是它几乎在所有语言中实现的原因,它是所有编程的美妙特性;-)

是的,我忘记提到的最令人难忘的区别是类支持数据隐藏,也支持在内置数据类型上执行的操作,而struct不支持!

根据c++编程语言中的Stroustrup:

你使用哪种风格取决于环境和品味。对于所有数据都是公共的类,我通常更喜欢使用struct。我认为这样的类“不是很合适的类型,只是数据结构”。

在功能上,除了public / private没有区别

结构的成员默认为public,类的成员默认为private。 结构从另一个结构或类的默认继承是公共的。类从其他结构或类的默认继承是私有的。

class A{    
public:    
    int i;      
};

class A2:A{    
};

struct A3:A{    
};


struct abc{    
    int i;
};

struct abc2:abc{    
};

class abc3:abc{
};


int _tmain(int argc, _TCHAR* argv[])
{    
    abc2 objabc;
    objabc.i = 10;

    A3 ob;
    ob.i = 10;

    //A2 obja; //privately inherited
    //obja.i = 10;

    //abc3 obss;
    //obss.i = 10;
}

这是在VS2005上。

引用c++ FAQ,

[7.8] What's the difference between the keywords struct and class? The members and base classes of a struct are public by default, while in class, they default to private. Note: you should make your base classes explicitly public, private, or protected, rather than relying on the defaults. Struct and class are otherwise functionally equivalent. OK, enough of that squeaky clean techno talk. Emotionally, most developers make a strong distinction between a class and a struct. A struct simply feels like an open pile of bits with very little in the way of encapsulation or functionality. A class feels like a living and responsible member of society with intelligent services, a strong encapsulation barrier, and a well defined interface. Since that's the connotation most people already have, you should probably use the struct keyword if you have a class that has very few methods and has public data (such things do exist in well designed systems!), but otherwise you should probably use the class keyword.

Iso iec14882 -2003 9类 §3 结构是用定义的类 类键结构体;它的成员 基类(第10条)是 默认为公开(第11条)。