Struct和Class的区别
今天这篇博文主要讲解在C++中关键字struct和class的区别。这篇博文，将会系统的将这两个关键字的不同面进行详细的讲解。
从语法上来讲，class和struct做类型定义时只有两点区别：
1.默认继承权限，如果不指定，来自class的继承按照private继承处理，来自struct的继承按照public继承处理；
2.成员的默认访问权限。class的成员默认是private权限，struct默认是public权限。以上两点也是struct和class最基本的差别，也是最本质的差别；
但是在C++中，struct进行了扩展，现在它已经不仅仅是一个包含不同数据类型的数据结构了，它包括了更多的功能。
Struct能包含成员函数吗？
是的，答案是肯定的。现在就让我写一段代码验证一下：
/*
** FileName : StructAndClassDiffDemo
** Author : Jelly Young
** Date : 2013/12/7
** Description : More information, please go to http://www.weikejianghu.com
*/
#include <iostream>
using namespace std;
struct Test
{
int a;
int getA()
{
return a;
}
void setA(int temp)
{
a = temp;
}
};
int main(int argc, char* argv[])
{
Test testStruct;
testStruct.setA(10);
cout<<"Get the value from struct:"<<testStruct.getA()<<endl;
Test *testStructPointer = new Test;
testStructPointer->setA(20);
cout<<"Get the value from struct again:"<<testStructPointer->getA()<<endl;
delete testStructPointer;
return 0;
}
</div>
以上的代码会很正确的运行，是的；没错，struct能包含成员函数的。
Struct有自己的构造函数吗？
是的，可以的。看以下测试代码：
/*
** FileName : StructAndClassDiffDemo
** Author : Jelly Young
** Date : 2013/12/7
** Description : More information, please go to http://www.weikejianghu.com
*/
#include <iostream>
using namespace std;
struct Test
{
int a;
Test()
{
a = 100;
}
int getA()
{
return a;
}
void setA(int temp)
{
a = temp;
}
};
int main(int argc, char* argv[])
{
Test testStruct;
testStruct.setA(10);
cout<<"Get the value from struct:"<<testStruct.getA()<<endl;
Test *testStructPointer = new Test;
testStructPointer->setA(20);
cout<<"Get the value from struct again:"<<testStruct.getA()<<endl;
delete testStructPointer;
// test the constructor
Test testConstructor;
cout<<"Set the value by the construct and get it:"<<testConstructor.getA()<<endl;
return 0;
}
</div>
Struct可以有析构函数么？
让我来验证一下：
/*
** FileName : StructAndClassDiffDemo
** Author : Jelly Young
** Date : 2013/12/7
** Description : More information, please go to http://www.weikejianghu.com
*/
#include <iostream>
using namespace std;
struct Test
{
int a;
Test()
{
a = 100;
}
int getA()
{
return a;
}
void setA(int temp)
{
a = temp;
}
~Test()
{
cout<<"Destructor function called."<<endl;
}
};
int main(int argc, char* argv[])
{
Test testStruct;
testStruct.setA(10);
cout<<"Get the value from struct:"<<testStruct.getA()<<endl;
Test *testStructPointer = new Test;
testStructPointer->setA(20);
cout<<"Get the value from struct again:"<<testStruct.getA()<<endl;
delete testStructPointer;
// test the constructor
Test testConstructor;
cout<<"Set the value by the construct and get it:"<<testConstructor.getA()<<endl;
return 0;
}
</div>
是的，完全支持析构函数。
Struct支持继承么？
再让我写代码验证一下：
/*
** FileName : StructAndClassDiffDemo
** Author : Jelly Young
** Date : 2013/12/7
** Description : More information, please go to http://www.weikejianghu.com
*/
#include <iostream>
using namespace std;
struct A
{
int a;
A()
{