C++字符串处理封装类String

概述

C++在处理字符串时相对于python等脚本语言并没有什么优势，下面将常用的字符串处理函数封装成一个String工具类，方便以后使用，后期还会对该类进行扩充，下面是具体的实现：

// String.hpp
#ifndef _STRING_HPP
#define _STRING_HPP

#include <string.h>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

class String
{
public:
    static std::string trimLeft(const std::string& str, const std::string& token = " ")
    {
        std::string t = str;
        t.erase(0, t.find_first_not_of(token));
        return t;
    }

    static std::string trimRight(const std::string& str, const std::string& token = " ")
    {
        std::string t = str;
        t.erase(t.find_last_not_of(token) + 1);
        return t;
    }

    static std::string trim(const std::string& str, const std::string& token = " ")
    {
        std::string t = str;
        t.erase(0, t.find_first_not_of(token));
        t.erase(t.find_last_not_of(token) + 1);
        return t;
    }

    static std::string toLower(const std::string& str)
    {
        std::string t = str;
        std::transform(t.begin(), t.end(), t.begin(), tolower);
        return t;
    }

    static std::string toUpper(const std::string& str)
    {
        std::string t = str;
        std::transform(t.begin(), t.end(), t.begin(), toupper);
        return t;
    }

    static bool	startsWith(const std::string& str, const std::string& substr)
    {
        return str.find(substr) == 0;
    }

    static bool endsWith(const std::string& str, const std::string& substr)
    {
        return str.rfind(substr) == (str.length() - substr.length());
    }

    static bool equalsIgnoreCase(const std::string& str1, const std::string& str2) 
    {
        return toLower(str1) == toLower(str2);
    }

    static std::vector<std::string> split(const std::string& str, const std::string& delimiter)
    {
        char* save = nullptr;
        char* token = strtok_r(const_cast<char*>(str.c_str()), delimiter.c_str(), &save);
        std::vector<std::string> result;
        while (token != nullptr)
        {
            result.emplace_back(token);
            token = strtok_r(nullptr, delimiter.c_str(), &save);
        }
        return result;
    }
};

#endif

下面是String的具体使用例子：

// main.cpp
#include <iostream>
#include "String.hpp"

int main()
{
    std::string str = "Hello world";
    std::cout << String::trimLeft(str, "Hello") << std::endl;
    std::cout << String::trimRight(str, "world") << std::endl;
    str = "  nihao ";
    std::cout << String::trim(str) << std::endl;
    std::cout << String::toUpper(str) << std::endl;
    std::cout << String::toLower(String::toUpper(str)) << std::endl;
    str = "Hello world";
    std::cout << String::startsWith(str, "Hello") << std::endl;
    std::cout << String::endsWith(str, "a") << std::endl;
    std::vector<std::string> result = String::split(str, " ");
    for (auto& iter : result)
    {
        std::cout << iter << std::endl;
    }

    return 0;
}

该例子的github地址：https://github.com/chxuan/samples/tree/master/String