length property Null safety
override
The number of objects in this list.
The valid indices for a list are 0 through length - 1.
final numbers = <int>[1, 2, 3];
print(numbers.length); // 3
Implementation
@override
final int length;override
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');
}