C++ STL之string常见用法

#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

int main()
{
    //可直接用cin输入，不可用scanf
    string s0;
    cin>>s0;
    cout<<s0<<endl;

    //可以用 = 讲数组中的值赋给string
    string s1;
    char s[1024];
    cin>>s;
    s1=s;
    cout<<s1<<endl;

    //可以直接用 = 赋值
    string s2;
    s2="hello";
    cout<<s2<<endl;

    //string的拼接，+号 和append()方法皆可
    s2+='-';
    s2+="world";
    s2.append("-2017");
    cout<<s2<<endl;

    //向string中插入单个字符
    s2.insert(s2.begin()+2,'x');
    cout<<s2<<endl;

    //删除string中某一位置的字符
    s2.erase(s2.begin()+2);
    //赋值为空串，相当于全部删除
    s1="";
    cout<<s1<<endl;
    cout<<s2<<endl;

    //string迭代器
    string::iterator it;
    for(it = s2.begin();it!=s2.end();it++)
    {
        cout<<*it<<' ';
    }
    cout<<endl;

    //find()可用于寻找元素第一次出现的数组下标
    cout<<s2.find('-')<<endl;
    cout<<s2.find("wor")<<endl;

    //逆置
    reverse(s2.begin(),s2.end());
    cout<<s2<<endl;

    //字典序排序
    sort(s2.begin(),s2.end());
    cout<<s2<<endl;

    //empty()判断是否为空
    cout<<s2.empty()<<endl;

    //判断string是否相等
    cout<<operator==(s2,s1)<<endl;

    //获得string子串
    cout<<s2.substr(2,5);

    //size()计算string中有多少个字符
    cout<<s2.size()<<endl;
    cout<<s2.length()<<endl;

    //at()输出某一确定位置的字符
    cout<<s2.at(2);

    return 0;
}