description

# singleOrNull property

T? get singleOrNull

The single element of this iterator, or `null`.

If the iterator has precisely one element, this is that element. Otherwise, if the iterator has zero elements, or it has two or more, the value is `null`.

## Implementation

    T? get singleOrNull {
      var iterator = this.iterator;
      if (iterator.moveNext()) {
        var result = iterator.current;
        if (!iterator.moveNext()) return result;
      }
      return null;
    }