/** Writes an integer with commas seperating the thousands places. */
commaify[n] :=
{
   result = new array
   for chunk = chunks[reverse[integerDigits[n]],3]
      result.pushFirst[joinstr[reverse[chunk]]]

   return join[",", result]
}

/*
println[commaify[1]]
println[commaify[12]]
println[commaify[123]]
println[commaify[1234]]
println[commaify[12345]]
println[commaify[123456]]
println[commaify[1234567]]
println[commaify[12345678]]
println[commaify[123456789]]
println[commaify[1234567890]]
println[commaify[12345678901]]
println[commaify[123456789012]]
*/