(C++) ReplaceAll

 

ReplaceAll is a std::string replace code snippet to replace a substring by another in a certain std::string.

 

There are multiple versions of ReplaceAll:

 

• ReplaceAll #1: uses Boost Strings Algorithm Library
• ReplaceAll #2: uses Qt library
• ReplaceAll #3: uses STL only

 

Below the code snippets a program that tests the ReplaceAll code snippets can be viewed and downloaded.

 

 

 

 

 

ReplaceAll #1: uses Boost Strings Algorithm Library

 

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#include <string> #include <boost/algorithm/string/replace.hpp> ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAll(   std::string s,   const std::string& before,   const std::string& after) {   return boost::algorithm::replace_all_copy(s,before,after); }

 

 

 

 

 

ReplaceAll #2: uses Qt library

 

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#include <string> #include <QString> ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAll(   std::string s,   const std::string& before,   const std::string& after) {   QString q(s.c_str());   q.replace(before.c_str(),after.c_str());   return q.toStdString(); }

 

 

 

 

 

ReplaceAll #3: uses STL only

 

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#include <string> ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAll(   std::string s,   const std::string& before,   const std::string& after) {   while(1)   {     const int pos = s.find(before);     if (pos==-1) break;     s.replace(pos,before.size(),after);   }   return s; }

 

 

 

 

 

Full testing code

 

• Download the Qt Creator project 'CppReplaceAll' (zip)

 

 

 

 

 

Technical facts

 

Application type(s)

• Desktop application

Operating system(s) or programming environment(s)

• Lubuntu 12.10 (quantal)

IDE(s):

• Qt Creator 2.5.2

C++ standard:

• C++98

Compiler(s):

• G++ 4.7.2

Libraries used:

• STL: GNU ISO C++ Library, version 4.7.2

 

 

 

 

 

Qt project file: CppReplaceAll.pro

 

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TEMPLATE = app CONFIG += console CONFIG += qt SOURCES += main.cpp

 

 

 

 

 

main.cpp

 

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#include <string> #include <boost/algorithm/string/replace.hpp> ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAllBoost(   std::string s,   const std::string& before,   const std::string& after) {   return boost::algorithm::replace_all_copy(s,before,after); } #include <QString> ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAllQt(   std::string s,   const std::string& before,   const std::string& after) {   QString q(s.c_str());   q.replace(before.c_str(),after.c_str());   return q.toStdString(); } ///Replaces all occurences of a substring //From http://www.richelbilderbeek.nl/CppReplaceAll.htm const std::string ReplaceAllStl(   std::string s,   const std::string& before,   const std::string& after) {   while(1)   {     const int pos = s.find(before);     if (pos==-1) break;     s.replace(pos,before.size(),after);   }   return s; } #include <cassert> int main() {   //Test single char replacement   {     //s: input string     //x: expected output string     //b: before     //a: after     const std::string s = "abcdbef";     const std::string x = "a_cd_ef";     const std::string b = "b";     const std::string a = "_";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test single char to multiple chars replacement   {     const std::string s = "abcdbef";     const std::string x = "a__cd__ef";     const std::string b = "b";     const std::string a = "__";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test single char to no char replacement   {     const std::string s = "abcdbef";     const std::string x = "acdef";     const std::string b = "b";     const std::string a = "";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test multiple chars to multiple chars replacement   {     const std::string s = "abcdbcef";     const std::string x = "a__d__ef";     const std::string b = "bc";     const std::string a = "__";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test multiple chars to more chars replacement   {     const std::string s = "abcdbcef";     const std::string x = "a___d___ef";     const std::string b = "bc";     const std::string a = "___";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test multiple chars to single char replacement   {     const std::string s = "abcdbcef";     const std::string x = "a_d_ef";     const std::string b = "bc";     const std::string a = "_";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   }   //Test multiple chars to no char replacement   {     const std::string s = "abcdbcef";     const std::string x = "adef";     const std::string b = "bc";     const std::string a = "";     assert(ReplaceAllBoost(s,b,a) == x);     assert(ReplaceAllQt(s,b,a) == x);     assert(ReplaceAllStl(s,b,a) == x);   } }