string成员函数
总体函数
代码语言：javascript复制#include <string>
#include <iostream>
using namespace std;
int main()
{
//构造函数
string str1 = "hello";
string* str2 = new string("hello");
string str3 = "world";
//获取字符长度
int n = str1.length();
//字符拼接
string str4 = str1 str3;
//获取字符串第一个字符
string::const_iterator it = str1.begin();
cout << *it << endl;
it = str1.end();
it--;
cout << *it << endl;
//字符串倒置
reverse(str1.begin(), str1.end());
//字符串转字符数组
string c = "abc123";
char *d = new char[20];
strcpy(d, c.c_str());//因为这里没有直接赋值，所以指针类型可以不用const char *
//访问
cout<<str1[1]<<endl;
cout<<str1.at(1)<<endl;
//查找
string st1("babbabab");
cout << st1.find('a') << endl;//1,默认从位置0（即第1个字符）开始查找
cout << st1.find('a', 2) << endl;//4 在st1中，从位置2（b，包括位置2）开始，查找a，返回首次匹配的位置
cout << (st1.find('c', 0) == -1) << endl;//1
string st2("aabcbcabcbabcc");
str1 = "abc";
cout << st2.find(str1, 2) << endl;//6,从st2的位置2（b）开始匹配，返回第一次成功匹配时匹配的串（abc）的首字符在st2中的位置，失败返回-1
cout << st2.find("abcdefg", 2, 3) << endl;//6 取abcdefg得前3个字符（abc）参与匹配，相当于st2.find("abc", 2)
//rfind-从指定位置起向前查找，直到串首
cout << st1.rfind('a', 7) << endl;//6
//find_first_of-在源串中从位置pos起往后查找，只要在源串中遇到一个字符，该字符与目标串中任意一个字符相同，就停止查找，返回该字符在源串中的位置；若匹配失败，返回-1
string str6("bcgjhikl");
string str7("kghlj");
cout << str6.find_first_of(str7, 0) << endl;//2,从str1的第0个字符b开始找，g与str2中的g匹配，停止查找，返回g在str1中的位置2
//find_last_of-与find_first_of函数相似，只不过查找顺序是从指定位置向前
string str("abcdecg");
cout << str.find_last_of("hjlywkcipn", 6) << endl;//5,从str的位置6(g)开始向前找，g不匹配，再找c，c匹配，停止查找，返回c在str中的位置5
//find_first_not_of-在源串中从位置pos开始往后查找，只要在源串遇到一个字符，与目标串中的任意字符都不相同，就停止查找，返回该字符在源串中的位置；若遍历完整个源串，都找不到满足条件的字符，则返回-1
cout << str.find_first_not_of("kiajbvehfgmlc", 0) << endl;//3 从源串str的位置0(a)开始查找，目标串中有a，匹配，..,找d，目标串中没有d（不匹配），停止查找，返回d在str中的位置3
//find_last_not_of-与find_first_not_of相似，只不过查找顺序是从指定位置向前
cout << str.find_last_not_of("kiajbvehfgmlc", 6) << endl;//3
return 0;
}常用函数
构造函数
代码语言：javascript复制 string strs //生成空字符串
string s(str) //生成字符串str的复制品
string s(str, stridx) //将字符串str中始于stridx的部分作为构造函数的初值
string s(str, strbegin, strlen) //将字符串str中始于strbegin、长度为strlen的部分作为字符串初值
string s(cstr) //以C_string类型cstr作为字符串s的初值
string s(cstr,char_len) //以C_string类型cstr的前char_len个字符串作为字符串s的初值
strings(num, c) //生成一个字符串，包含num个c字符
strings(strs, beg, end)
//以区间[beg, end]内的字符作为字符串s的初值
std::string s('x'); //错误
std::string s(1, 'x'); //正
std::string s("x"); //正确析构函数
代码语言：javascript复制~string() //销毁所有内存，释放内存示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string str ("12345678");
char ch[ ] = "abcdefgh";
string a; //定义一个空字符串
string str_1 (str); //构造函数，全部复制
string str_2 (str, 2, 5); //构造函数，从字符串str的第2个元素开始，复制5个元素，赋值给str_2
string str_3 (ch, 5); //将字符串ch的前5个元素赋值给str_3
string str_4 (5,'X'); //将 5 个 'X' 组成的字符串 "XXXXX" 赋值给 str_4
string str_5 (str.begin(), str.end()); //复制字符串 str 的所有元素，并赋值给 str_5
cout << str << endl;
cout << a << endl ;
cout << str_1 << endl;
cout << str_2 << endl;
cout << str_3 << endl;
cout << str_4 << endl;
cout << str_5 << endl;
return 0;
}
迭代器
代码语言：javascript复制const_iterator begin()const;
iterator begin(); //返回string的起始位置
const_iterator end()const;
iterator end(); //返回string的最后一个字符后面的位置
const_iterator rbegin()const;
iterator rbegin(); //返回string的最后一个字符的位置
const_iterator rend()const;
iterator rend(); //返回string第一个字符位置的前面示例
代码语言：javascript复制 #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main ()
{
string s ("The zip code of Hondelage in Germany is 38108.");
cout << "Original: " << s << endl;
string sd(s.begin(),s.end ()); //构造函数中使用迭代器
cout << "Destination: " << sd << endl;
// transform (sd.begin(), sd.end(), sd.begin(), toupper); //算法中使用迭代器(仿函数)
// cout << "Destination (All Toupper)): " << sd << endl;
string sd1;
sd1.append (sd.begin(),(sd.end() -7)); //append()函数中使用迭代器
cout << "Destination sd1: " << sd1 << endl;
string sd2;
string::reverse_iterator iterA;
string temp = "0";
for (iterA = sd.rbegin (); iterA != sd.rend (); iterA ) //reverse_iterator
{
temp=* iterA;
sd2.append (temp);
}
cout << "Destination sd2: " << sd2 << endl;
sd2.erase (0, 15); //erase()函数中使用迭代器
cout << "Destination sd2 (Erased 15 chars) : " << sd2 << endl;
string::iterator iterB = sd2.begin ();
string sd3 = string ("12345678");
sd2.insert (sd2.begin(), sd3.begin(), sd3.end()); //insert()函数中使用迭代器
cout << "Destination sd2 (Insert 8 chars) : " << sd2 << endl;
sd2.replace (sd2.begin (), sd2.end(), "This is an Exarrple of Replace"); //Replace
cout <<"Destination sd2 (Replace All): " << sd2 << endl; // replace ()函数中使用迭代器
}
字符长度
代码语言：javascript复制int capacity()const; //返回当前容量（即string中不必增加内存即可存放的元素个数）
int max_size()const; //返回string对象中可存放的最大字符串的长度
int size()const; //返回当前字符串的大小
int length()const; //返回当前字符串的长度
bool empty()const; //当前字符串是否为空
void resize(int len,char c);//把字符串当前大小置为len，并用字符c填充不足的部分示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
int size = 0;
int length = 0;
unsigned long maxsize = 0;
int capacity=0;
string str ("12345678");
string str_custom;
str_custom = str;
str_custom.resize (5);
size = str_custom.size();
length = str_custom.length();
maxsize = str_custom.max_size();
capacity = str_custom.capacity();
cout << "size = " << size << endl;
cout << "length = " << length << endl;
cout << "maxsize = " << maxsize << endl;
cout << "capacity = " << capacity << endl;
return 0;
}
输入流
代码语言：javascript复制 string input("hello,this is a test");
istringstream is(input);
string s1,s2,s3,s4;
is>>s1>>s2>>s3>>s4;//s1="hello,this",s2="is",s3="a",s4="test"
ostringstream os;
os<<s1<<s2<<s3<<s4;
cout<<os.str()
//2
getline(istream &in,string &s); //用于从输入流in中读取字符串到s中，以换行符'n'分开
//eg:
string s1;
getline (cin, s1); // 实现了读取一行字符，包括空格、制表符、回车符等行内字符和符号，以n分开示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string s1, s2;
getline(cin, s1);
getline(cin, s2, ' ');
cout << "You inputed chars are: " << s1 << endl;
cout << "You inputed chars are: " << s2 << endl;
}
访问元素
代码语言：javascript复制const char &operator[](int n)const;
const char &at(int n)const;
char &operator[](int n);
char &at(int n);示例
1
代码语言：javascript复制 #include <iostream>
#include <string>
int main()
{
const std::string cS ("c.biancheng.net");
std::string s ("abode");
char temp =0;
char temp_1 = 0;
char temp_2 = 0;
char temp_3 = 0;
char temp_4 = 0;
char temp_5 = 0;
temp = s [2]; //"获取字符 'c'
temp_1 = s.at(2); //获取字符 'c'
temp_2 = s [s.length()]; //未定义行为，返回字符' '，但Visual C 2012执行时未报错
temp_3 = cS[cS.length()]; //指向字符 ' '
//temp_4 = s.at (s.length ()); //程序异常
// temp_5 = cS.at(cS.length ()); //程序异常
std::cout << temp <<temp_1 << temp_2 << temp_3<<std::endl;
// std::cout<< temp_4 << temp_5 << std::endl;
return 0;
}2
代码语言：javascript复制 #include <iostream>
#include <string>
int main()
{
std::string s ("abode");
std::cout << s << std::endl ;
char& r = s[2] ; //建立引用关系
char*p=&s[3]; //建立引用关系
r='X' ;//修改内容
*p='Y' ;//修改内容
std::cout << s << std::endl; //输出
s = "12345678"; //重新赋值
r ='X'; //修改内容
*p='Y'; //修改内容
std::cout << s << std::endl; //输出
return 0;
}
字符串比较
代码语言：javascript复制
int compare(const string &s) const;//比较当前字符串和s的大小
int compare(int pos, int n,const string &s)const;//比较当前字符串从pos开始的n个字符组成的字符串与s的大小
int compare(int pos, int n,const string &s,int pos2,int n2)const;//比较当前字符串从pos开始n个字符字符串与s中pos2开始n2个字符字符串的大小
int compare(const char *s) const;
int compare(int pos, int n,const char *s) const;
int compare(int pos, int n,const char *s, int pos2) const;示例
代码语言：javascript复制#include <iostream>
#include <string>
using namespace std;
int main ()
{
string A ("aBcdef");
string B ("AbcdEf");
string C ("123456");
string D ("123dfg");
//下面是各种比较方法
int m=A.compare (B); //完整的A和B的比较
int n=A.compare(1,5,B,4,2); //"Bcdef"和"AbcdEf"比较
int p=A.compare(1,5,B,4,2); //"Bcdef"和"Ef"比较
int q=C.compare(0,3,D,0,3); //"123"和"123"比较
cout << "m = " << m << ", n = " << n <<", p = " << p << ", q = " << q << endl;
cin.get();
}
删除
代码语言：javascript复制iterator erase(iterator first, iterator last);//删除[first，last）之间的所有字符，返回删除后迭代器的位置
iterator erase(iterator it);//删除it指向的字符，返回删除后迭代器的位置
string &erase(int pos = 0, int n = npos);//删除pos开始的n个字符，返回修改后的字符串赋值
代码语言：javascript复制 basic_string& assign (const E*s); //直接使用字符串赋值
basic_string& assign (const E*s, size_type n);
basic_string& assign (const basic_string & str, size_type pos, size_type n);
//将str的子串赋值给调用串
basic_string& assign (const basic_string& str); //使用字符串的“引用”賦值
basic_string& assign (size_type n, E c) ; //使用 n个重复字符賦值
basic_string& assign (const_iterator first, const_iterator last); //使用迭代器赋值示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main()
{
string str1 ("123456");
string str;
str.assign (str1); //直接赋值
cout << str << endl;
str.assign (str1, 3, 3); //赋值给子串
cout << str << endl;
str.assign (str1,2,str1.npos);//赋值给从位置 2 至末尾的子串
cout << str << endl;
str.assign (5,'X'); //重复 5 个'X'字符
cout << str << endl;
string::iterator itB;
string::iterator itE;
itB = str1.begin ();
itE = str1.end();
str.assign (itB, (--itE)); //从第 1 个至倒数第 2 个元素，赋值给字符串 str
cout << str << endl;
return 0;
}
插入
代码语言：javascript复制string &insert(int p0, const char *s);
string &insert(int p0, const char *s, int n);
string &insert(int p0,const string &s);
string &insert(int p0,const string &s, int pos, int n);
//前4个函数在p0位置插入字符串s中pos开始的前n个字符
string &insert(int p0, int n, char c);//此函数在p0处插入n个字符c
iterator insert(iterator it, char c);//在it处插入字符c，返回插入后迭代器的位置
void insert(iterator it, const_iterator first, const_iterator last);//在it处插入[first，last）之间的字符
void insert(iterator it, int n, char c);//在it处插入n个字符c示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string str1 ("123456");
string str2 ("abcdefghijklmn");
string str;
str.assign(str1);
cout << str << endl;
str.assign (str1 , 3, 3);
cout << str << endl;
str.assign (str1, 2, str1.npos);
cout << str << endl;
str.assign (5, 'X');
cout << str << endl;
string::iterator itB;
string::iterator itE;
itB = str1.begin ();
itE = str1.end();
str.assign (itB, (--itE));
cout << str << endl;
str = str1;
cout << str << endl;
str.erase(3);
cout << str << endl;
str.erase (str.begin (), str.end());
cout << ":" << str << ":" << endl;
str.swap(str2);
cout << str << endl;
string A ("ello");
string B ("H");
B.insert (1, A);
cout << B << endl;
A = "ello";
B ='H';
B.insert (1, "yanchy ", 3);
cout << "插入: " << B << endl;
A = "ello";
B = "H";
B.insert(1,A,2,2);
cout << "插入:" << B << endl;
A = "ello";
B = "H";
B.insert (1,5,'C');
cout << "插入:" << B << endl;
A = "ello";
B = "H";
string::iterator it = B.begin () 1;
const string::iterator itF = A.begin ();
const string::iterator itG = A.end ();
B.insert(it,itF,itG);
cout<<"插入："<< B << endl;
A = "ello";
B = "H";
cout << "A = " << A <<", B = " << B << endl ;
B.append (A);
cout << "追加：" << B << endl;
B = "H";
cout << "A = "<< A << ", B= " << B << endl;
B.append("12345", 2);
cout << "追加：" << B << endl;
A = "ello";
B = "H";
cout << "A = " << A << ", B= " << B << endl;
B.append ("12345", 2, 3);
cout << "追加：" << B << endl;
A = "ello";
B = "H";
cout << "A = " << A <<", B = " << B << endl;
B.append (10 , 'a');
cout << "追加:"<< B << endl;
A = "ello";
B = "H";
cout << "A = " << A << ", B = " << B << endl;
B.append(A.begin() , A.end());
cout << "追加:" << B << endl;
cin.get();
return 0;
}
替换
代码语言：javascript复制string &replace(int p0, int n0,const char *s);//删除从p0开始的n0个字符，然后在p0处插入串s
string &replace(int p0, int n0,const char *s, int n);//删除p0开始的n0个字符，然后在p0处插入字符串s的前n个字符
string &replace(int p0, int n0,const string &s);//删除从p0开始的n0个字符，然后在p0处插入串s
string &replace(int p0, int n0,const string &s, int pos, int n);//删除p0开始的n0个字符，然后在p0处插入串s中从pos开始的n个字符
string &replace(int p0, int n0,int n, char c);//删除p0开始的n0个字符，然后在p0处插入n个字符c
string &replace(iterator first0, iterator last0,const char *s);//把[first0，last0）之间的部分替换为字符串s
string &replace(iterator first0, iterator last0,const char *s, int n);//把[first0，last0）之间的部分替换为s的前n个字符
string &replace(iterator first0, iterator last0,const string &s);//把[first0，last0）之间的部分替换为串s
string &replace(iterator first0, iterator last0,int n, char c);//把[first0，last0）之间的部分替换为n个字符c
string &replace(iterator first0, iterator last0,const_iterator first, const_iterator last);//把[first0，last0）之间的部分替换成[first，last）之间的字符串抽取
代码语言：javascript复制string substr(int pos = 0,int n = npos) const;//返回pos开始的n个字符组成的字符串示例
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string var ("abcdefghijklmn");
const string dest ("1234");
string dest2 ("567891234");
var.replace (3,3, dest);
cout << "1: " << var << endl;
var = "abcdefghijklmn";
var.replace (3,1, dest.c_str(), 1, 3);
cout << "2: " << var << endl;
var ="abcdefghijklmn";
var.replace (3, 1, 5, 'x');
cout << "3: " << var << endl;
string::iterator itA, itB;
string::iterator itC, itD;
itA = var.begin();
itB = var.end();
var = "abcdefghijklmn";
var.replace (itA, itB, dest);
cout << "4: " << var << endl;
itA = var.begin ();
itB = var.end();
itC = dest2.begin () 1;
itD = dest2.end ();
var = "abodefghijklmn";
var.replace (itA, itB, itC, itD);
cout << "5: " << var << endl;
var = "abcdefghijklmn";
var.replace (3, 1, dest.c_str(), 4); //这种方式会限定字符串替换的最大长度
cout <<"6: " << var << endl;
return 0;
}
查找
代码语言：javascript复制int find(char c, int pos = 0) const;//从pos开始查找字符c在当前字符串的位置
int find(const char *s, int pos = 0) const;//从pos开始查找字符串s在当前串中的位置
int find(const char *s, int pos, int n) const;//从pos开始查找字符串s中前n个字符在当前串中的位置
int find(const string &s, int pos = 0) const;//从pos开始查找字符串s在当前串中的位置
//查找成功时返回所在位置，失败返回string::npos的值
int rfind(char c, int pos = npos) const;//从pos开始从后向前查找字符c在当前串中的位置
int rfind(const char *s, int pos = npos) const;
int rfind(const char *s, int pos, int n = npos) const;
int rfind(const string &s,int pos = npos) const;
//从pos开始从后向前查找字符串s中前n个字符组成的字符串在当前串中的位置，成功返回所在位置，失败时返回string::npos的值
int find_first_of(char c, int pos = 0) const;//从pos开始查找字符c第一次出现的位置
int find_first_of(const char *s, int pos = 0) const;
int find_first_of(const char *s, int pos, int n) const;
int find_first_of(const string &s,int pos = 0) const;
//从pos开始查找当前串中第一个在s的前n个字符组成的数组里的字符的位置。查找失败返回string::npos
int find_first_not_of(char c, int pos = 0) const;
int find_first_not_of(const char *s, int pos = 0) const;
int find_first_not_of(const char *s, int pos,int n) const;
int find_first_not_of(const string &s,int pos = 0) const;
//从当前串中查找第一个不在串s中的字符出现的位置，失败返回string::npos
int find_last_of(char c, int pos = npos) const;
int find_last_of(const char *s, int pos = npos) const;
int find_last_of(const char *s, int pos, int n = npos) const;
int find_last_of(const string &s,int pos = npos) const;
int find_last_not_of(char c, int pos = npos) const;
int find_last_not_of(const char *s, int pos = npos) const;
int find_last_not_of(const char *s, int pos, int n) const;
int find_last_not_of(const string &s,int pos = npos) const;
//find_last_of和find_last_not_of与find_first_of和find_first_not_of相似，只不过是从后向前查找示例
1
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string str_ch (" for");
string str (" Hi, Peter, I'm sick. Please bought some drugs for me.");
string::size_type m= str.find ('P', 5);
string::size_type rm= str.rfind('P', 5);
cout << "Example - find() : The position (forward) of 'P' is: " << (int) m << endl;
cout << "Example - rfind(): The position (reverse) of 'P' is: " << (int) rm << endl;
string::size_type n = str.find (" some", 0);
string::size_type rn = str.rfind (" some", 0);
cout << "Example - find () : The position (forward) of 'some' is: " << (int) n << endl;
cout << "Example - rfind () : The position (reverse) of 'some' is: " << (int) rn << endl;
string::size_type mo = str.find (" drugs", 0, 5);
string::size_type rmo = str.rfind (" drugs", 0, 5);
cout << "Example - find(): The position (forward) of 'drugs' is: " << (int) mo << endl;
cout << "Example - rfind(): The position (reverse) of 'drugs' is: " << (int) rmo << endl;
string::size_type no = str.find (str_ch, 0);
string::size_type rno = str.rfind(str_ch, 0);
cout << "Example - find (): The position of 'for' is: " << (int) no << endl;
cout << "Example - rfind(): The position of 'for' is: " << (int) rno << endl;
cin.get ();
}
2
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string str_ch ("for");
string str("Hi, Peter, I'm sick. Please bought some drugs for me. ");
int length = str.length();
string::size_type m = str.find_first_of ('P', 0);
string::size_type rm = str.find_last_of ('P', (length - 1));
cout << "Example - find_first_of (): The position (forward) of 'P' is: " << (int) m << endl;
cout << "Example - find_last_of (): The position (reverse) of 'P' is：" << (int) rm << endl;
string:: size_type n = str.find_first_of ("some", 0);
string:: size_type rn = str.find_last_of ("some", (length -1));
cout << "Example - find_first_of(): The position (forward) of 'some' is: " << (int) n << endl;
cout << "Example - find_last_of(): The position (reverse) of 'some' is: " << (int) rn << endl;
string:: size_type mo = str.find_first_of ("drugs", 0, 5);
string:: size_type rmo = str.find_last_of ("drugs", (length-1), 5);
cout << "Example - find_first_of () : The position (forward) of 'drugs' is: " << (int) mo << endl;
cout << "Example - find_last_of () : The position (reverse) of 'drugs' is: " << (int) rmo << endl;
string::size_type no = str.find_first_of (str_ch, 0);
string::size_type rno = str.find_last_of (str_ch, (length -1));
cout << "Example - find_first_of() : The position of 'for' is: " << (int) no << endl;
cout << "Example - find_last_of () : The position of 'for' is: " << (int) rno << endl;
cin.get();
return 0;
}
3
代码语言：javascript复制 #include <iostream>
#include <string>
using namespace std;
int main ()
{
string str_ch (" for");
string str ("Hi, Peter, I'm sick. Please bought some drugs for me.");
int length = str.length ();
string::size_type m= str.find_first_not_of ('P',0);
string::size_type rm= str.find_last_not_of ('P', (length -1));
cout << "Example - find_first_of (): The position (forward) of 'P' is: " << (int) m << endl;
cout << "Example - find_last_of (): The position (reverse) of 'P' is: " << (int) rm << endl;
string:: size_type n = str.find_first_not_of ("some", 0);
string:: size_type rn = str.find_last_not_of ("some", (length -1));
cout << "Example - find_first_of (): The position (forward) of 'some' is: " << (int) n << endl;
cout << "Example - find_last_of (): The position (reverse) of 'some' is: " << (int) rn << endl;
string:: size_type mo = str.find_first_not_of ("drugs", 0, 5);
string:: size_type rmo = str.find_last_not_of ("drugs", (length-1), 5);
cout << "Example - find_first_of (): The position (forward) of 'drugs' is: " << (int) mo << endl;
cout << "Example - find_last_of (): The position (reverse) of 'drugs' is: " << (int) rmo << endl;
string::size_type no = str.find_first_not_of (str_ch, 0);
string::size_type rno = str.find_last_not_of (str_ch, (length-1));
cout << "Example - find_first_of (): The position of 'for' is: " << (int) no << endl;
cout << "Example - find_last_of () : The position of 'for' is: " << (int) rno << endl;
cin.get ();
return 0;
}
附加：
auto_ptr
引入：
代码语言：javascript复制void f()
{
Type* pt(new Type);
//一些代码...
delete pt;
}
void f()
{
auto_ptr<Type> pt(new Type);
//一些代码...
}同样的功能，auto_ptr省去了delete[]
示例：
代码语言：javascript复制#include <iostream>
#include <memory>
using namespace std;
void f(auto_ptr<int> aptr)
{
cout<<*aptr<<endl;
}
int main()
{
auto_ptr<int> aptr(new int(10));
f(aptr);
cout<<*aptr<<endl;//错误，经过f函数调用,原有的aptr已经不再拥有任何对象了
// get：返回auto_ptr指向的那个对象的内存地址
int *p=new int(10);
cout << "the adress of p: "<< p << endl;
auto_ptr<int> aptr(p);
cout << "the adress of aptr: " << &aptr << endl;
cout << "the adress of the object which aptr point to: "
<< aptr.get() << endl;
// reset：重新设置auto_ptr指向的对象，
// 类似于赋值操作，但是赋值操作不允许将一个普通指针直接赋值给auto_ptr，而reset允许
auto_ptr<string> aptr(new string("name"));
aptr.reset(new string("sex"));
cout<<*(aptr.get())<<endl;
cout<<*aptr<<endl;
//release：返回auto_ptr指向的那个对象的内存地址，并且释放这个对象的所有权
//用此函数初始化auto_ptr可以避免两个auto_ptr对象指向同一个对象的情况
auto_ptr<string> aptr(new string("name"));
auto_ptr<string> aptr1(aptr.get());//这是两个auto_ptr拥有同一个对象
auto_ptr<string> aptr2(aptr.release());//release可以先释放所有权，这样就不会指向同一个对象
return 0;
}
