This code snippet works for both Dart and JS.

This code is written in JavaScript, not Dart, correct?

In fact, this will need to be done in any case, even if it is the first method call. In the worst case scenario where the searched element is the last, this will not be very good for large volumes of data, as was indicated in the condition

nice bro good solution

did not know the function singleOrNull thx for that :)

Suggestions to improve the code:

• the change function can be inlined since it's a simple swap operation. Swift has a built-in swapAt method for arrays,
• the final case conversion loop can be combined with the first loop to avoid iterating over the array multiple times.

This line of code
if (iterable[i] != iterable[i+1]) res.push(iterable[i]);

can result on out of bounds

I solved this kata, but you implement clever.

Sorry that is not best practices, there is a formular for this problem, which is much more efficient.

Parenthesis are unnecessary since && has higher precedence than ||

Arrow function, great solution!!

Cool