charEncode method
Implementation
String? charEncode(int dec) {
switch (dec) {
case 10:
return 'A';
case 11:
return 'B';
case 12:
return 'C';
case 13:
return 'D';
case 14:
return 'E';
case 15:
return 'F';
default:
if(dec<10&&dec>=0){
return '$dec';
}
return null;
}
}