主函数
cpp
#include"head.h"
int main()
{
My_string s2("hello");
My_string s3(5,'A');
s2.show();
s3.show();
My_string s1=s2;
s1.show();
My_string s4;
s4=s3;
s4.show();
if(s4.empty_if())
{
cout<<"该字符数组为空"<<endl;
}
else
{
cout<<"该字符数组不为空"<<endl;
}
s1.push_back('!');
s1.show();
s1.pop_back();
s1.show();
cout << "第一个位置是 : " << s1.at(1) << endl;
s1.clear();
s1.show();
cout << "s2当前的长度是 : " << s2.get_length()<<"s3当前的最大容量是"<<s3.get_size()<<endl;
return 0;
}
头文件:
cpp
#ifndef HEAD_H
#define HEAD_H
#include <iostream>
#include <cstring>
using namespace std;
class My_string
{
private:
char *ptr; //指向字符数组的指针
int size; //字符串的最大容量
int len; //字符串的当前容量
public:
My_string();
My_string(const char *src);
My_string(int num,char value);
My_string(const My_string &other);
My_string &operator=(const My_string &other);
void show();
bool empty_if();
void push_back(char value);
void pop_back();
char &at(int index);
void clear();
int get_length();
int get_size();
~My_string();
};
#endif // HEAD_H
源文件:
cpp
#include"head.h"
using namespace std;
My_string::My_string():size(15)
{
this->ptr =new char[size];
this->ptr [0]='\0';
this->len=0;
}
My_string::My_string(const char *src)
{
this->len=strlen(src);
this->size=this->len+1;
this->ptr =new char[size];
strcpy(this->ptr,src);
}
My_string::My_string(int num,char value)
{
this->len=num;
this->size=this->len+1;
this->ptr =new char[num];
for(int i=0;i<5;i++)
{
this->ptr[i]=value;
}
}
My_string::My_string(const My_string &other)
{
this->len = other.len;
this->size = other.size;
this->ptr = new char[size]; // 分配新的内存
strcpy(this->ptr, other.ptr); // 复制源对象的字符串内容
}
My_string&My_string ::operator=(const My_string &other)
{
if(this != &other) //防止自己给自己赋值
{
this->size = other.size;
this->len = other.len;
this->ptr = new char[size];
strcpy(this->ptr ,other.ptr); //深拷贝
}
return *this; //返回值自身的引用
}
void My_string::show()
{
cout<<this->ptr<<endl;
}
My_string::~My_string()
{
delete this->ptr;
}
bool My_string::empty_if()
{
return this->len==0;
}
void My_string::push_back(char value)
{
ptr[len] = value; // 在尾部添加字符
ptr[len+1] = '\0'; // 确保字符串以空字符结尾
this->len++;
}
void My_string::pop_back()
{
if (this->len > 0) // 确保字符串非空
{
ptr[len-1] = '\0'; // 更新终止符
this->len--;
}
}
char &My_string::at(int index)
{
return ptr[index-1]; // 返回引用以支持修改
}
void My_string::clear()
{
this->len = 0; // 重置长度为 0
ptr[0] = '\0'; // 以空字符结束
}
int My_string::get_length()
{
return this->len;
}
int My_string::get_size()
{
return this->size;
}