Eliminating Last Comma & Space [duplicate]

Answer 1

Generally you don't know number of values to print up-front (but in your case it's 4). So it is easier to print separator before instead of after. No ifs:

String sep="";
for (i = 0; i < NUM_VALS; i++) {
     System.out.print(sep + hourlyTemp[i]);
     sep=", ";
  }

Trick is - first time there is nothing to separate hence separator is empty, later - ", ";

Fits into register, saves branch predictor's work. Calculating if (i == last_value) is not 0 cost as well.