I would think you'd want to start by placing the first item at 'dtmf[0]' and not 'dtmf[1]'
Try ...
dtmf[i++]= mapKey();
I would think you'd want to start by placing the first item at 'dtmf[0]' and not 'dtmf[1]'
Try ...
dtmf[i++]= mapKey();