c++ 去除字符串首尾的空白字符
方法一使用find_first_not_of和find_last_not_of方法二使用正则表达式(c++11)测试测试结果方法一使用find_first_not_of和find_last_not_of
/*** @brief Trimmed 去掉首尾 空格白* @param str*/void Trimmed(std::string& str) {str.erase(0, str.find_first_not_of(" \r\n\t\v\f"));str.erase(str.find_last_not_of(" \r\n\t\v\f") + 1);// std::cout << "Trimmed [" << str << "]" << std::endl;}
方法二使用正则表达式(c++11)
/*** @brief Trimmed_Regex 正则表达式 去字符串首尾的 空白 c++ 11* @param str*/void Trimmed_Regex(std::string& str) {std::regex e("([\\S].*[\\S])");str = std::regex_replace (str,e,"$1",std::regex_constants::format_no_copy);// std::cout << "Trimmed_Regex [" << str << "]" << std::endl;//std::cout << "Trimmed_Regex [" << std::regex_replace (str,e,"$2") << "]" << std::endl;}
测试
int main() {//std::string str ("there is a subsequence in the string\n");//std::regex e ("\\b(sub)([^ ]*)"); // matches words beginning by "sub"//// using string/c-string (3) version://std::cout << std::regex_replace (s,e,"sub-$2");//// using range/c-string (6) version://std::cout << result;//// with flags://std::cout << std::regex_replace (s,e,"$1 and $2",std::regex_constants::format_no_copy);//std::cout << std::endl;clock_t start;std::string str = "\r\n \t\v\f { Test 123 78927849……&*%&*&*（【】）代收款} \t\v\f \r\n";std::cout << "[" << str << "]" << std::endl;start = clock();Trimmed_Regex(str);std::cout << clock() - start << " Trimmed_Regex [" << str << "]" << std::endl;start = clock();Trimmed(str);std::cout << clock() - start << " Trimmed [" << str << "]" << std::endl;//std::string result;//std::regex_replace (std::back_inserter(result), str.begin(), str.end(), e, "");// std::cout << "[" << result << "]" << std::endl;return 0;}
