简介
本文主要介绍在C++中struct与class的主要区别
默认访问权限
- class的默认访问权限是private
- struct的默认访问权限是public
例程
#include <iostream>
class CTest
{
int class_member; //默认访问属性：private
};
struct STest
{
int struct_member; //默认访问属性:public
};
int main()
{
CTest classTest;
STest structTest;
//提示错误：member "CTest::class_member" is inaccessible
//classTest.class_member = 30;
structTest.struct_member = 10;
std::cout << "struct's member: " << structTest.struct_member << "\n";
system("pause");
return 0;
}
输出值：
struct's member: 10
默认的继承访问权限
- class的默认继承访问权限是private
- struct的默认继承访问权限是public
例程
#include <iostream>
class CTest
{
public:
int class_member;
};
class CDerived :CTest // default access specifier is private
{
};
struct STest
{
int struct_member;
};
struct SDerived :STest //defautl access specifier is public
{
};
int main()
{
SDerived s_derived;
CDerived c_derived;
s_derived.struct_member = 100;
//Error:class "CDerived" has no member "struct_member"
// because default access specifier is private for class
//c_derived.struct_member = 200;
std::cout << "s_derived.struct_member= " << s_derived.struct_member << "\n";
return 0;
}
//输出结果
s_derived.struct_member= 100
struct与class之间混合继承
-
什么是混合继承？
答：好吧，这是我自己想的，指通过struct去继承class,或通过class去继承struct
- 通过struct默认继承class,继承方式为public继承
- 通过class默认继承struct,继承方式为private继承
例程
#include <iostream>
class CTest
{
public:
int class_member;
};
struct SDerivedClass :CTest // 相当于 struct sDerivedClass: public CTest{}；
{
};
struct STest
{
int struct_member;
};
class CDerivedStruct :STest // 相当于class CDerivedStruct: private STest{}；
{
};
int main()
{
SDerivedClass sDerived;
CDerivedStruct cDerived;
sDerived.class_member = 100;
//Error: "struct_member" is not a member of "CDerived"
//cDerived.struct_member = 200;
std::cout << "sDerived.class_member: " << sDerived.class_member << "\n";
return 0;
}
输出结果：
sDerived.class_member: 100
