avoid-accessing-collections-by-constant-index

added in: 1.10.0

warning

Warns when a collection is accessed by a constant index inside a for loop.

Example

❌ Bad:

const _array = [1, 2, 3, 4, 5, 6, 7, 8, 9];

void func() {
  for (final element in _array) {
    _array[0]; // LINT
    _array[element];
    _array[constIndex]; // LINT
    _array[finalIndex]; // LINT
    _array[mutableIndex];
    _array[Some.index]; // LINT
    _array[Some.mutableIndex];
  }
}

class Some {
  static final index = 1;
  static int mutableIndex = 1;
}

const constIndex = 1;
final finalIndex = 1;
var mutableIndex = 1;

✅ Good:

const _array = [1, 2, 3, 4, 5, 6, 7, 8, 9];

void func() {
  _array[0];
  _array[constIndex];
  _array[finalIndex];
  _array[Some.index];

  for (final element in _array) {
    _array[element];
    _array[mutableIndex];
    _array[Some.mutableIndex];
  }
}

class Some {
  static final index = 1;
  static int mutableIndex = 1;
}

const constIndex = 1;
final finalIndex = 1;
var mutableIndex = 1;