C++primer_顺序容器之string操作

#include <iostream>
#include<string>
#include<vector>
using namespace  std;
void replace_string(string &s, const string &oldVal, const string &newVal)//最原始的字符串迭代器进行对比替换
{
auto l = oldVal.size();
if (!l)
return;
auto iter = s.begin();
while (iter <= s.end() - 1)
{
auto iter1 = iter;
auto iter2 = oldVal.begin();
while (iter2 !=oldVal.end()&& *iter1==*iter2)
{
iter1++;
iter2++;
}
if (iter2 == oldVal.end())
{
iter = s.erase(iter, iter1);
if (newVal.size())
{
iter2 == newVal.end();//出现错误直接崩溃
do
{
iter2--;
iter = s.insert(iter, *iter2);
} while (iter2>newVal.begin());
}
iter += newVal.size();
}
else iter++;
}
}

void replacestring(string&s, const string &oldVal, const string &newVal)//直接利用标准库里面的函数操作字符串极大地简化了string的操作
{
int p = 0;
while ((p=s.find(oldVal,p))!=string::npos)
{
s.replace(p, oldVal.size(), newVal);
p += newVal.size();
}
}

void name_string(string&name, const string &prefix, const string &suffix)//利用迭代器来进行插入和尾增操作
{
name.insert(name.begin(), 1, ' ');
name.insert(name.begin(), prefix.begin(), prefix.end());
name.append(" ");
name.append(suffix.begin(), suffix.end());
}
void namestring(string &name, const string&prefix, const string &suffix)//按长度和位置进行string管理
{
name.insert(0, " ");
name.insert(0, prefix);
name.insert(name.size(), " ");
name.insert(name.size(), suffix);

}
void find_char(string&s, const string&chars)//直接利用find_first_of(s,chars)函数进行查找返回值为一个string::npos的特殊值，有返回字符串，没有返回npos
{
cout << "在" << s << "中查找" << chars << "中字符" << endl;
string::size_type pos = 0;
while ((pos = s.find_first_of(chars,pos))!=string::npos)
{
cout << "pos: " << pos<<",char: " << s[pos] << endl;
pos++;
}
}

void find_not_char(string&s, const string&chars)//直接利用find_first_of(s,chars)函数进行查找返回值为一个string::npos的特殊值，有返回字符串，没有返回npos
{
cout << "在" << s << "中查找不在" << chars << "中字符" << endl;
string::size_type pos = 0;
while ((pos = s.find_first_not_of(chars, pos)) != string::npos)
{
cout << "pos: " << pos << ",char: " << s[pos] << endl;
pos++;
}
}
float SumStringInt(const vector<string> &sub)//无限整数相加，不牵扯整数大小可以是stoi(string)到int,也可以是stof(string)是float
{
auto sum=0;
for (auto iter = sub.begin(); iter != sub.end(); iter++)
sum += stof(*iter);
return sum;
}

int main(int argc, char **argv)
{

string s = "tho thru  tho !";
//replacestring(s, "thru", "through");
//replace_string(s, "thru", "through");
name_string(s, "nihao", "wobuhao");
cout << s << endl;
string p = "123sdv546dbjy64vs4";
find_char(p, "1234567890");
find_not_char(p, "1234567890");
vector<string>sumint{"12","3456","+102","-129","+12"};
cout << SumStringInt(sumint)<<endl;
system("pause");
return 0;
}