查找搜索
一般使用 find, rfind 即可，如果找不到，返回 std::npos.
size_t find (const string& str, size_t pos = 0) const;
size_t find (const char* s, size_t pos = 0) const;
string s1("Source Code");
int n;
if ((n = s1.find('u')) != string::npos) //查找 u 出现的位置
cout << "1) " << n << "," << s1.substr(n) << endl;
//输出 l)2,urce Code
if ((n = s1.find("Source", 3)) == string::npos)
//从下标3开始查找"Source"，找不到
cout << "2) " << "Not Found" << endl; //输出 2) Not Found
参考:
学习笔记 c++ （在String查找子串和字符 ）
https://blog.csdn.net/qq_42145185/article/details/101025298
c++ string类字符串查找
https://blog.csdn.net/qq_45797026/article/details/108359461
C++ string类中的字符串查找
https://blog.csdn.net/cywosp/article/details/7280466
C++字符串查找函数详解
http://c.biancheng.net/view/1453.html
字符串查找函数，C语言字符串查找函数详解
http://c.biancheng.net/view/340.html
删除特定字符
先用 remove 把字符移动，再用 erase 删除这些字符。
str.erase(std::remove(str.begin(), str.end(), 'a'), str.end());
参考:
C++从string中删除所有的某个特定字符
https://www.cnblogs.com/7z7chn/p/6341453.html
C++ remove、remove_copy、remove_if和remove_copy_if函数使用详解
http://c.biancheng.net/view/617.html
分割
使用 find 和 substr 配合
size_type find( const basic_string& str, size_type pos = 0 ) const;
basic_string substr( size_type pos = 0, size_type count = npos ) const;
// 使用字符串分割
void Stringsplit(const string& str, const string& splits, vector<string>& res)
{
if (str == "") return;
//在字符串末尾也加入分隔符，方便截取最后一段
string strs = str + splits;
size_t pos = strs.find(splits);
int step = splits.size();
// 若找不到内容则字符串搜索函数返回 npos
while (pos != strs.npos)
{
string temp = strs.substr(0, pos);
res.push_back(temp);
//去掉已分割的字符串,在剩下的字符串中进行分割
strs = strs.substr(pos + step, strs.size());
pos = strs.find(splits);
}
}
参考:
C++中string如何实现字符串分割函数split()
https://blog.csdn.net/weixin_43919932/article/details/111304250
C++string字符串split的6种方法
https://zhuanlan.zhihu.com/p/426939341
C++ find()函数用法详解（超级详细）
http://c.biancheng.net/view/7489.html
trim
c++11 支持
#include <algorithm>
#include <cctype>
#include <locale>
// trim from start (in place)
static inline void ltrim(std::string &s) {
s.erase(s.begin(), std::find_if(s.begin(), s.end(), [](unsigned char ch) {
return !std::isspace(ch);
}));
}
// trim from end (in place)
static inline void rtrim(std::string &s) {
s.erase(std::find_if(s.rbegin(), s.rend(), [](unsigned char ch) {
return !std::isspace(ch);
}).base(), s.end());
}
// trim from both ends (in place)
static inline void trim(std::string &s) {
ltrim(s);
rtrim(s);
}
// trim from start (copying)
static inline std::string ltrim_copy(std::string s) {
ltrim(s);
return s;
}
// trim from end (copying)
static inline std::string rtrim_copy(std::string s) {
rtrim(s);
return s;
}
// trim from both ends (copying)
static inline std::string trim_copy(std::string s) {
trim(s);
return s;
}
#include <algorithm>
#include <functional>
#include <cctype>
#include <locale>
// trim from start (in place)
static inline void ltrim(std::string &s) {
s.erase(s.begin(), std::find_if(s.begin(), s.end(),
std::not1(std::ptr_fun<int, int>(std::isspace))));
}
// trim from end (in place)
static inline void rtrim(std::string &s) {
s.erase(std::find_if(s.rbegin(), s.rend(),
std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
}
// trim from both ends (in place)
static inline void trim(std::string &s) {
ltrim(s);
rtrim(s);
}
// trim from start (copying)
static inline std::string ltrim_copy(std::string s) {
ltrim(s);
return s;
}
// trim from end (copying)
static inline std::string rtrim_copy(std::string s) {
rtrim(s);
return s;
}
// trim from both ends (copying)
static inline std::string trim_copy(std::string s) {
trim(s);
return s;
}
参考:
c++ 中关于string trim问题
https://www.cryogeny.cn/1310.html
C++实现trim()函数
https://blog.csdn.net/hugoo_hu/article/details/7947837
C语言写的trim()函数
https://www.cnblogs.com/liushui-sky/p/5584763.html
C++ Best way to trim std::string
https://cppsecrets.com/users/41129711010797106994610011511264103109971051084699111109/C00-Best-way-to-trim-stdstring.php