学习string容器总结

# include<iostream>
# include<cstdio>
# include<algorithm>
# include<cstdlib>
# include<string>
# include<vector>
using namespace std;
int main(int argc,const char *argv[])
{
    /*------------------------------------------*/
    //length
    //string s;
    //s = "abc123456";
    //cout<<s.length()<<endl;
    //s = "";
    //cout<<s.empty()<<endl;

    /*------------------------------------------*/
    //string赋值的两种形式
    //<1>
    //string s;
    //s = "hello,c++ stl";
    //cout<<s<<endl;
    //<2>
    // string s;
    //char ss[5000];
    //scanf比cin快。。。
    //scanf是c语言的函数，不支持string对象
    //scanf("%s",&ss);
    //s = ss;
    //cout<<s<<endl;


    /*------------------------------------------*/
    //从对象尾部添加字符
    //string s;
    //s = s + 'a';
    //s = s + 'b';
    // s = s + 'c';
    //cout<<s<<endl;
    //cout<<s.size()<<endl;

    /*------------------------------------------*/
    //从string对象尾部追加字符串
    //<1>
    //string s;
    //s = s+"abc";
    //s = s+"123";
    //cout<<s<<endl;
    //<2>
    //string s;
    //s.append("abc");
    //s.append("123");
    //cout<<s<<endl;

    /*------------------------------------------*/
    //给string对象插入字符
    //string s;
    //s = "123456";
    //string::iterator it;
    //it = s.begin();
    //it = s.insert(it+1,'p');
    //cout<<s<<endl;

    /*---------------------------------------*/
    //访问string对象的元素
    //string s;
    //s = "abc123456";
    //cout<<s[0]<<endl;
    //cout<<s[0]-'a'<<endl;

    //string::iterator it;
    //for(it = s.begin();it!=s.end();it++)
    //{
    //    cout<<*it<<" ";
    //}

    /*--------------------------------------*/
    //删除指定的串
    //string s;
    //s = "abc123456";
    // string::iterator it;
    // it = s.begin();
    // s.erase(it+3);
    // cout<<s<<endl;
    // s.erase(it,it+3);
    // cout<<s<<endl;
    // s = "";
    // cout<<s.length()<<endl;

    /*---------------------------------------*/
    //替换string对象的字符
    //string s;
    // s = "abc123456";
    //从第3个数开始，将连续的3个字符替换为“good”
    //即将“123”替换为“good”
    //s.replace(3,3,"good");
    //cout<<s<<endl;

    /*---------------------------------------*/
    //搜索string对象的元素或子串
    //string s;
    //s = "cat dog cat";
    //cout<<s.find('c')<<endl;
    //cout<<s.find("c")<<endl;
    //cout<<s.find("cat")<<endl;
    //cout<<s.find("dog")<<endl;
    //cout<<s.find("dogc")<<endl;

    /*---------------------------------------*/
    //string对象的比较
    //string s;
    //s = "cat dog cat";
    //cout<<s.compare("cat")<<endl;
    //cout<<s.compare("cat dog cat")<<endl;
    //cout<<s.compare("dog")<<endl;

    /*--------------------------------------*/
    //reveser转置
    //string s;
    // s = "123456789";
    //reverse(s.begin(),s.end());
    //cout<<s<<endl;

    /*--------------------------------------*/
    //vector在string的应用
    //vector<string>v;
    //v.push_back("Jack");
    //v.push_back("Michael");
    //v.push_back("Miao");
    //cout<<v[0]<<endl;
    //cout<<v[1]<<endl;
    //cout<<v[2]<<endl;
    //cout<<v[0][0]<<endl;
    //cout<<v[1][0]<<endl;
    //cout<<v[2].length()<<endl;

    /*--------------------------------------*/
    //string s;
    //s = "1234059";
    //int i;
    //int sum = 0;
    //for(i = 0; i < s.length(); i++)
    //{
    //    if(s[i] == '0') sum+=0;
    //    else if(s[i] == '1') sum+=1;
    //    else if(s[i] == '2') sum+=2;
    //    else if(s[i] == '3') sum+=3;
    //    else if(s[i] == '4') sum+=4;
    //    else if(s[i] == '5') sum+=5;
    //    else if(s[i] == '6') sum+=6;
    //    else if(s[i] == '7') sum+=7;
    //    else if(s[i] == '8') sum+=8;
    //    else if(s[i] == '9') sum+=9;
    // }
    // cout<<sum<<endl;

    /*---------------------------------*/
    //string s;
    //char ss[100];
    //scanf("%s",&ss);
    //s=ss;
    //printf(s.c_str());
    //cout<<endl;
    //printf("%s",ss);
    //cout<<endl;
    //cout<<s<<endl;
    //cout<<ss<<endl;

    /*----------------------------------*/
    //string 和scanf函数
    //string s1,s2,s3;
    //char sa[100],sb[100],sc[100];
    //将字符串分离成字串，分隔符为空格
    //sscanf("abc 123 pc","%s %s %s",&sa,&sb,&sc);
    //s1 = sa;
    //s2 = sb;
    //s3 = sc;
    //cout<<s1<<" "<<s2<<" "<<s3<<endl;
    //将字符串分离成数字，分隔符为空格
    //当用到数字的时候，跟scanf一样，踏要指针地址
    //int a,b,c;
    //sscanf("1 2 3","%d %d %d",&a,&b,&c);
    //cout<<a<<" "<<b<<" "<<c<<endl;
    //将字符串分离成数字，分隔符为“，”和“$”
    //当用到数字的时候，跟scanf一样，它要传指针地址
    //int x,y,z;
    //sscanf("4,5$6","%d,%d$%d",&x,&y,&z);
    //cout<<x<<" "<<y<<" "<<z<<endl;

    /*----------------------------------------------*/
    //string对象与数值相互转换（写法有问题）
    //string convertToString(double x)//C++方法，将数值转换为string
    //{
    //    ostringstream o;
    //   if(o<<x)
    //   return o.str();
    //   return "conversion error";
    //}
    //double convertFromString(const string &s)//C++方法，将string转换为数值
    //{
    //    istringstream (s);
    //    double x;
    //    if(i >>x)
    //   return x;
    //   return 0.0;
    //}
    //int main(int argc,const char* argv[])
    //{
    //将数值转换为string的第一种方法：C方法
    //char b[10];
    // string a;
    // sprinf(b,"%d",1975);
    // a = b;
    // cout<<a<<endl;
    //将数值转化为string的第二种的方法：C++方法
    // string cc = convertToString(1976);
    // cout<<cc<<endl;
    //将string转化为数值的方法：C++方法
    // string dd=  "2006";
    //int p = convertFromString(dd)+2;
    //cout<<p<<endl;
    //}
    return 0;
}