How to remove all substrings from a string

Question

How to remove all instances of the pattern from a string?

string str = \"red tuna, blue tuna, black tuna, one tuna\";
string pattern = \"tuna\";

Answer 1

This is a basic question and you'd better take a look at the string capabilities in the standard library.

Classic solution

#include 
#include 

int main() { 
   std::string str = "red tuna, blue tuna, black tuna, one tuna";
   std::string pattern = "tuna";

   std::string::size_type i = str.find(pattern);
   while (i != std::string::npos) {
     str.erase(i, pattern.length());
     i = str.find(pattern, i);
   }

   std::cout << str;
}

Example

RegEx solution

Since C++11 you have another solution (thanks Joachim for reminding me of this) based on regular expressions

#include 
#include 
#include 

int main() { 
   std::string str = "red tuna, blue tuna, black tuna, one tuna";
   std::regex pattern("tuna");

   std::cout << std::regex_replace(str, pattern, "");
}

Example