operator [] method Null safety

Rectangle<num> operator [] (
  1. int index
)
override

The object at the given index in the list.

The index must be a valid index of this list, which means that index must be non-negative and less than length.

Implementation

Rectangle operator [](int index) {
  if (JS("bool", "# >>> 0 !== # || # >= #", index, index, index, length))
    throw new RangeError.index(index, this);
  return JS("Rectangle", "#[#]", this, index);
}