string str1 = "abcdefg";
rfind 是从右往左查早 find 是从左往右查找
cout << str1.find("e") << endl;
cout << str1.rfind("ef") << endl;
//字符串替换//
str1.replace(1, 3, "1111");
cout << str1 << endl;
//字符串比较
string str2 = "abcdfg";
if (str1.compare(str2) == 0)
{
cout << "str1 == str2" << endl;
}
//访问字符串元素
for (int i = 0;i < str1.size();i++)
cout << str1[i] << " " << endl;
for (int i = 0;i < str1.size();i++)
cout << str1.at(i)<< " " << endl;
//修改字符串元素
str1[0] = 'x';
str1.at(1) = 'x';
cout << str1 << endl;
//字符串插入
str1.insert(1, "111");
cout << str1 << endl;
//字符串删除
str1.erase(1, 3);//第一个位置开始删除三个
cout << str1 << endl;
//从字符串中获取子串
string substr = str1.substr(1, 3);//从第一个元素开始截取3个
cout << substr << endl;
//实用操作 截取用户名
string email = "[email protected]";
int pos = email.find('@');
string UseName = email.substr(0, pos);
cout << UseName << endl;