Discussion on: Daily Challenge #2 - String Diamond

import 'dart:io';

main(){
  stdout.writeln('Center Lenght?');
  int center = int.tryParse(stdin.readLineSync());
  if(center == null || center%2 == 0){
    print('Center can\'t be null or an even number');
  }

  for(var i = 1; i < center; i+=2){
    print((" " * ((center - i) ~/ 2 )) + ("*" * i));
  }
  for(var i = center; i >= 1; i-=2){
    print((" " * ((center - i) ~/ 2 )) + ("*" * i));
  }
}