firstNonNull function

dynamic firstNonNull (
  1. dynamic o1,
  2. dynamic o2,
  3. [dynamic o3,
  4. dynamic o4]

Returns the first non-null argument. If all arguments are null, throws an ArgumentError.

Note: if o1 is an Optional, this can be accomplished with o1.or(o2).


firstNonNull(o1, o2, [o3, o4]) {
  if (o1 != null) return o1;
  if (o2 != null) return o2;
  if (o3 != null) return o3;
  if (o4 != null) return o4;
  throw new ArgumentError('All arguments were null');