List<E>.filled constructor Null safety

List<E>.filled(
  1. int length,
  2. E fill,
  3. {bool growable: false}
)

Creates a list of the given length with fill at each position.

The length must be a non-negative integer.

Example:

List<int>.filled(3, 0, growable: true); // [0, 0, 0]

The created list is fixed-length if growable is false (the default) and growable if growable is true. If the list is growable, increasing its length will not initialize new entries with fill. After being created and filled, the list is no different from any other growable or fixed-length list created using [] or other List constructors.

All elements of the created list share the same fill value.

var shared = List.filled(3, []);
shared[0].add(499);
print(shared);  // => [[499], [499], [499]]

You can use List.generate to create a list with a fixed length and a new object at each position.

var unique = List.generate(3, (_) => []);
unique[0].add(499);
print(unique); // => [[499], [], []]

Implementation

external factory List.filled(int length, E fill, {bool growable = false});