string pasting

C (and therefore C++ too) lets you create string literals by pasting several literals together. This is achieved by placing them adjacently. So "the quick brown fox" and "the quick" "brown fox" are 2 ways of specifying the same string literal. Note that this only works for string literals; you cannot expect C to give character arrays any special treatment.

What's it good for? Good question, but there are good reasons to use it:

1. Split a long literal along several lines of code:

   printf("The rain it raineth on the just\n"
          "And also un the unjust fella.\n"
          "But chiefly on the just;\n"
          "For the unjust's stolen the just's umbrella.\n");
   

2. Incorporate C preprocessor constants in the string:

   #define XYZ "letters"
   char xyz<> = "XYZ = \"" XYZ "\"";
   

   See also int32 for a real-world example.
3. Incorporate stringified preprocessor values in the string. See #x and the stringize macro macro hack for examples.