//////////////////////////////////////////////////////////////////////////
// -以下为头文件定义#include"StringToNumber.h"
#include<boost/regex.hpp>//正则表达式的头文件
// #include<vector>//其实上面的代码会自动包含此头文件
// #include<string> //其实上面的代码会自动包含此头文件
// ---------------------------------------------------------------------------
// ==============================================================================
// 为标准C++库<std::string>服务
// ==============================================================================
std::vector<std::string>FindDoubleString(std::string &Inputstring) {
std::vector<std::string>Outputstring;
std::string regstr =
"([-|+]?//d+//.//d+[e|E][+|-]//d+|[-|+]?//.//d+[e|E][+|-]//d+|[-|+]?//d+//.//d{0,}|[-|+]?//d+|[-|+]?//.//d+)";
boost::regex expression(regstr);
boost::smatch what;
std::string::const_iterator start = Inputstring.begin();
std::string::const_iterator end = Inputstring.end();
while (boost::regex_search(start, end, what, expression)) {
std::string msg(what[1].first, what[1].second); // 提取匹配字符
Outputstring.push_back(msg); // 将匹配结果放在vs中
start = what[0].second; // 从此位置再次搜索
};
return Outputstring;
};
// ==============================================================================
// UnicodeString For C++ Builder
// ==============================================================================
std::vector<String>FindDoubleString(String &InputString) {
std::string Inputstring = InputString.t_str();
std::vector<String>OutputString;
std::string regstr =
"([-|+]?//d+//.//d+[e|E][+|-]//d+|[-|+]?//.//d+[e|E][+|-]//d+|[-|+]?//d+//.//d{0,}|[-|+]?//d+|[-|+]?//.//d+)";
boost::regex expression(regstr);
boost::smatch what;
std::string::const_iterator start = Inputstring.begin();
std::string::const_iterator end = Inputstring.end();
while (boost::regex_search(start, end, what, expression)) {
std::string msg(what[1].first, what[1].second); // 提取匹配字符
OutputString.push_back(msg.c_str()); // 将匹配结果放在vs中
start = what[0].second; // 从此位置再次搜索
};
return OutputString;
};
//////////////////////////////////////////////////////////////////////////
////1.StringToDouble
//////////////////////////////////////////////////////////////////////////
bool StringToDouble(String Str, double &dbl) {
bool IsValid = false;
std::vector<String>OutputString = FindDoubleString(Str);
if (OutputString.size() > 0) {
dbl = OutputString[0].ToDouble();
IsValid = true;
}
return IsValid;
};
// ==============================================================================
// 在string中查找整数integer
// ==============================================================================
std::vector<std::string>FindIntegerString(std::string &Inputstring) {
std::vector<std::string>Outputstring;
std::string regstr = "([-|/+]?//d{1,10})";
boost::regex expression(regstr);
boost::smatch what;
std::string::const_iterator start = Inputstring.begin();
std::string::const_iterator end = Inputstring.end();
while (boost::regex_search(start, end, what, expression)) {
std::string msg(what[1].first, what[1].second); // 提取匹配字符
Outputstring.push_back(msg); // 将匹配结果放在vs中
start = what[0].second; // 从此位置再次搜索
};
return Outputstring;
};
// ==============================================================================
// UnicodeString For C++ Builder 在String中查找整数integer
// ==============================================================================
std::vector<String>FindIntegerString(String &InputString) {
std::string Inputstring = InputString.t_str();
std::vector<String>OutputString;
std::string regstr = "([-|/+]?//d{1,10})";
boost::regex expression(regstr);
boost::smatch what;
std::string::const_iterator start = Inputstring.begin();
std::string::const_iterator end = Inputstring.end();
while (boost::regex_search(start, end, what, expression)) {
std::string msg(what[1].first, what[1].second); // 提取匹配字符
OutputString.push_back(msg.c_str()); // 将匹配结果放在vs中
start = what[0].second; // 从此位置再次搜索
};
return OutputString;
};
// ==============================================================================
// StringToInteger 如果返回值为真,则Int被正确赋值
// ==============================================================================
//////////////////////////////////////////////////////////////////////////
////1.StringToInteger
//////////////////////////////////////////////////////////////////////////
bool StringToInteger(String Str, int &Int) {
bool IsValid = false;
std::vector<String>OutputString = FindIntegerString(Str);
if (OutputString.size() > 0) {
Int = OutputString[0].ToInt();
IsValid = true;
}
return IsValid;
};
//////////////////////////////////////////////////////////////////////////
// -以上为头文件定义#include"StringToNumber.h"
//==============================================================================
// 以下为测试程序
//==============================================================================
//
#include <vcl.h>
#pragma hdrstop
#include <tchar.h>
// ---------------------------------------------------------------------------
#include<iostream>
#include"StringToNumber.h"
// using namespace std;
// using namespace boost;
// ---------------------------------------------------------------------------
#pragma argsused
// ---------------------------------------------------------------------------
int _tmain(int argc, _TCHAR* argv[]) {
try {
std::string teststring = " -192.0+16.0a8.4hg93.sfe..e9.2s1+1.23e+3";
std::vector<std::string>vstr;
vstr = FindDoubleString(teststring);
std::cout << "teststring" << std::endl;
std::cout << teststring << std::endl;
std::cout << "vstr" << std::endl;
for (unsigned i = 0; i < vstr.size(); i++) {
std::cout << "<" << vstr[i] << ">";
}
std::cout <<std::endl;
// ==============================================================================
// UnicodeString
// ==============================================================================
String testString = " -192.0+16.0a8.4hg93.sfe..e9.2s1+1.23e+3";
std::vector<String>VStr;
VStr = FindDoubleString(testString);
std::cout << "testString" << std::endl;
std::cout << testString.t_str() << std::endl;
std::cout << "vstr" << std::endl;
for (unsigned i = 0; i < VStr.size(); i++) {
std::cout << "<" << VStr[i].t_str() << ">";
}
std::cout <<std::endl;
// ==============================================================================
// 测试StringToDouble
// ==============================================================================
double d = 0;
String dStr = " 3498203.38403";
// StringToDouble();
if (StringToDouble(dStr, d)) {
std::cout << "成功d= " << d << std::endl;
}
else {
std::cout << "转换失败" << std::endl;
}
std::cout <<std::endl;
// ==============================================================================
// 在string中查找整数integer
// ==============================================================================
teststring = " -192.0+16.0a8.4hg93.sfe..e9.2s1+1.23e+3";
vstr = FindIntegerString(teststring);
std::cout << "teststring" << std::endl;
std::cout << teststring << std::endl;
std::cout << "vstr" << std::endl;
for (unsigned i = 0; i < vstr.size(); i++) {
std::cout << "<" << vstr[i] << ">";
}
// ---------------------------------------------------------------------------
// ==============================================================================
// 测试StringToInteger
// ==============================================================================
int i = 0;
String iStr = " 3498203.38403";
std::cout <<std::endl;
if (StringToInteger(iStr, i)) {
std::cout << "成功i= " <<i << std::endl;
}
else {
std::cout << "转换失败" << std::endl;
}
// ---------------------------------------------------------------------------
std::getchar();
}
catch(...) {
}
return 0;
}
// ---------------------------------------------------------------------------
本文介绍了一种使用正则表达式从字符串中提取浮点数和整数的方法，并提供了将提取到的字符串转换为数值类型的实用函数。通过具体的示例展示了如何在C++中实现这些功能。
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