gotcha

gotcha
 n.

   A {misfeature} of a system, especially a programming language or
   environment, that tends to breed bugs or mistakes because it is both
   enticingly easy to invoke and completely unexpected and/or
   unreasonable in its outcome. For example, a classic gotcha in {C} is
   the fact that if (a=b) {code;} is syntactically valid and sometimes
   even correct. It puts the value of b into a and then executes code if
   a is non-zero. What the programmer probably meant was if (a==b)
   {code;}, which executes code if a and b are equal.
    

gotcha

   <jargon, programming> A {misfeature} of a system, especially a
   programming language or environment, that tends to breed
   {bugs} or mistakes because it both enticingly easy to invoke
   and completely unexpected and/or unreasonable in its outcome.

   For example, a classic gotcha in {C} is the fact that

   	if (a=b) {code;}

   is syntactically valid and sometimes even correct.  It puts
   the value of "b" into "a" and then executes "code" if "a" is
   non-zero.  What the programmer probably meant was

   	if (a==b) {code;}

   which executes "code" if "a" and "b" are equal.

   [{Jargon File}]

   (1995-04-17)