# length property

int length

Returns the number of elements in this.

Counting all elements may involve iterating through all elements and can therefore be slow. Some iterables have a more efficient way to find the number of elements.

## Implementation

    int get length {
      assert(this is! EfficientLengthIterable);
      int count = 0;
      Iterator it = iterator;
      while (it.moveNext()) {
        count++;
      }
      return count;
    }