C++快速入门---动态内存管理(23)
静态内存:变量(包括指针变量)、固定长度的数组、某给定类的对象
动态内存:由一些没有名字、只有地址的内存块构成的,那些内存块是在程序运行期间动态分配的。
用new向内存池申请内存
用delete来释放内存
注意:在用完内存块之后,应该用delete语句把它还给内存池。另外作为一种附加的保险措施,在释放了内存块之后还应该把与之关联的指针设置为NULL。
#include <iostream>
#include <string>
class Company
{
public:
Company(std::string theName);
virtual void printInfo();
protected:
std::string name;
};
class TechCompany : public Company
{
public:
TechCompany(std::string theName, std::string product);
virtual void printInfo();
private:
std::string product;
};
Company::Company(std::string theName)
{
name = theName;
}
void Company::printInfo()
{
std::cout << "这个公司的名字叫:" << name << ".\n";
}
TechCompany::TechCompany(std::string theName, std::string product) : Company(theName)
{
this->product = product;
}
void TechCompany::printInfo()
{
std::cout << name << "公司大量生产了 " << product << "这款产品!\n";
}
int main()
{
Company *company = new Company("APPLE");
company->printInfo();
delete company;
company = NULL;
company = new TechCompany("APPLE", "IPHONE");
company->printInfo();
delete company;
company = NULL;
return 0;
}