#include<iostream>
#include<cstring>
using namespace std;
class mystring
{
public:
mystring(char *s);
mystring();
~mystring();//虚构函数用来释放动态内存
void addstring(char *s);//连接两个字符串
void stringup(char *s);//字符串大写换小写
void change(char *s);//改变字符串
void show();//输出字符串
private:
int len;
char *p;
};
mystring::mystring(char *s)
{
len=strlen(s);
p=new char [len+1];
strcpy(p,s);
}
mystring::mystring()
{
len=0;
p=new char [len+1];
}
mystring::~mystring()
{
delete []p;
len=0;
}
void mystring::addstring(char *s)
{
int tlen=strlen(s);
char *temp=new char [len+1];
strcpy(temp,p);
delete []p;
p=new char [len+tlen+1];//p的动态内存重新申请
strcpy(p,temp);
strcat(p,s);
delete temp;//释放临时动态内存
}
void mystring::stringup(char *s)
{
int i;
if(p!=NULL)
delete []p;
len=strlen(s);
p=new char [len+1];
strcpy(p,s);
for(i=0;i<len;i++)
{
if(p[i]>='a'&&p[i]<='z')
{
//s[i]=s[i]-32;b不行
p[i]=s[i]-32;
}
}
}
void mystring::change(char *s)
{
delete []p;
len=strlen(s);
p=new char [len+1];
strcpy(p,s);
}
void mystring::show()
{
cout<<p<<endl;
}
void main()
{
mystring ms("awdseswsa");
ms.show();
ms.addstring("123");
ms.show();
ms.change("dedede");
ms.show();
ms.stringup("abc");
ms.show();
} |