Creates a list of the given length.
The created list is fixed-length if
length is provided.
List fixedLengthList = new List(3); fixedLengthList.length; // 3 fixedLengthList.length = 1; // Error
The list has length 0 and is growable if
length is omitted.
List growableList = new List(); growableList.length; // 0; growableList.length = 3;
To create a growable list with a given length, just assign the length right after creation:
List growableList = new List()..length = 500;
length must not be negative or null, if it is provided.
external factory List([int length]);