C++ 字符串处理-去除字符串前后的空字符

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1. 关键词
2. strutil.h
3. strutil.cpp
4. 测试代码
5. 运行结果
6. 源码地址

1. 关键词

C++ 字符串处理去除字符串前后的空字符跨平台

2. strutil.h

#include <string>
namespace cutl
{/*** @brief Remove leading whitespaces from a string.** @param str the string to be stripped.* @return std::string the stripped string.*/std::string lstrip(const std::string &str);/*** @brief Remove trailing whitespaces from a string.** @param str the string to be stripped.* @return std::string the stripped string.*/std::string rstrip(const std::string &str);/*** @brief Remove leading and trailing whitespaces from a string.** @param str the string to be stripped.* @return std::string the stripped string.*/std::string strip(const std::string &str);
} // namespace cutl

3. strutil.cpp

#include <cctype>
#include <algorithm>
#include "strutil.h"namespace cutl
{std::string lstrip(const std::string &str){if (str.empty()){return "";}size_t index = 0;for (size_t i = 0; i < str.length(); i++){if (!std::isspace(str[i])){index = i;break;}}return str.substr(index, str.length() - index);}std::string rstrip(const std::string &str){if (str.empty()){return "";}size_t index = str.length() - 1;for (size_t i = str.length() - 1; i >= 0; i--){if (!std::isspace(str[i])){index = i;break;}}return str.substr(0, index + 1);}std::string strip(const std::string &str){if (str.empty()){return "";}size_t index1 = 0;for (size_t i = 0; i < str.length(); i++){if (!std::isspace(str[i])){index1 = i;break;}}size_t index2 = str.length() - 1;for (size_t i = str.length() - 1; i >= 0; i--){if (!std::isspace(str[i])){index2 = i;break;}}auto len = index2 - index1 + 1;return str.substr(index1, len);}
} // namespace cutl

4. 测试代码

#include "common.hpp"
#include "strutil.h"void TestStrip()
{PrintSubTitle("TestStrip");std::string text = "  \tThis is a test string. \n ";// std::string text = "  \t中国 \n ";std::cout << "text: " << text << std::endl;std::cout << "trim left text: " << cutl::lstrip(text) << std::endl;std::cout << "trim right text: " << cutl::rstrip(text) << std::endl;std::cout << "trim text: " << cutl::strip(text) << std::endl;
}

5. 运行结果

---------------------------------------------TestStrip----------------------------------------------
text:   	This is a test string. trim left text: This is a test string. trim right text:   	This is a test string.
trim text: This is a test string.