length property

int get length

Setting the length changes the number of elements in the list.

The list must be growable. If newLength is greater than current length, new entries are initialized to null, so newLength must not be greater than the current length if the element type E is non-nullable.

final maybeNumbers = <int?>[1, null, 3];
maybeNumbers.length = 5;
print(maybeNumbers); // [1, null, 3, null, null]
maybeNumbers.length = 2;
print(maybeNumbers); // [1, null]

final numbers = <int>[1, 2, 3];
numbers.length = 1;
print(numbers); // [1]
numbers.length = 5; // Throws, cannot add `null`s.

Implementation

@override
final int length;

@override set length (int newLength)

Setting the length changes the number of elements in the list.

The list must be growable. If newLength is greater than current length, new entries are initialized to null, so newLength must not be greater than the current length if the element type E is non-nullable.

final maybeNumbers = <int?>[1, null, 3];
maybeNumbers.length = 5;
print(maybeNumbers); // [1, null, 3, null, null]
maybeNumbers.length = 2;
print(maybeNumbers); // [1, null]

final numbers = <int>[1, 2, 3];
numbers.length = 1;
print(numbers); // [1]
numbers.length = 5; // Throws, cannot add `null`s.

Implementation

@override
set length(int newLength) {
  throw UnsupportedError('Cannot change the length of a fixed-length list');
}