Parse string and swap substrings

Question

How can I parse a string given by a user and swap all occurrences of the old substring with the new string. I have a function to work with but I am really uncertain when it comes to strings.

void spliceSwap( char* inputStr, const char* oldStr, const char* newStr  )

Is this in C or C++? If it's C++, use `std::string`. If it's C, tag it appropriately. — Luchian Grigore, Jul 03 '13 at 19:30
Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work. See also: Stack Overflow question checklist — Brian Roach, Jul 03 '13 at 19:30

score 2 · Accepted Answer · edited May 23 '17 at 12:29

2

The simplest solution is to use google (First link) here. Also be aware that in C++ we prefer std::string over const char *. Do not write your own std::string, use the built-in one. Your code seems to be more C than C++!

edited May 23 '17 at 12:29

Community

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answered Jul 03 '13 at 19:33

CyberGuy

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score 0 · Answer 2 · edited Jul 05 '13 at 07:51

// Zammbi's variable names will help answer your  question   
// params find and replace cannot be NULL
void FindAndReplace( std::string& source, const char* find, const char* replace )
{
   // ASSERT(find != NULL);
   // ASSERT(replace != NULL);
   size_t findLen = strlen(find);
   size_t replaceLen = strlen(replace);
   size_t pos = 0;

   // search for the next occurrence of find within source
   while ((pos = source.find(find, pos)) != std::string::npos)
   {
      // replace the found string with the replacement
      source.replace( pos, findLen, replace );

      // the next line keeps you from searching your replace string, 
      // so your could replace "hello" with "hello world" 
      // and not have it blow chunks.
      pos += replaceLen; 
   }
}

Parse string and swap substrings

2 Answers2

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