revert words ina sentence C

revert.C

#include <stdio.h>

void revertWord( char *start, char *end ) {
   char temp;
   while( start < end ) {
      temp = *start;
      *start = *end;
      *end = temp;
      ++start;
      --end;
   }
}

void revertString(char *sentence) {

   char *start = sentence;
   char *end = sentence;

   while ( *(++end) ); // to the null 
   // but don't touch not null
   --end;

   // all sentence first
   revertWord( start, end );

   // and now word by word
   while ( *start ) { // not null?

     // find space if any, move start to it
     for (; *start && *start == ' '; ++start );

     // find end fo the word, move end to it
     for ( end = start; *end && *end != ' '; ++end );
     // space or null, back one
     --end;

     // reverse from start to end
     revertWord( start, end );

     // next word or null
     start = ++end;
   }
}

int main() {
   char test[] = "The quick brown fox jumped over the lazy dog.";
   printf( "before: %s\n", test );
   revertString(test);
   printf( "after: %s\n", test );
   return 0;
}