Linked List - Purpose of Callback Function

[halitaydin]

Hello folks,

I need to know purpose of callback function in find method in linked-list class. Is that callback function require for usage or not so important? If yes, how can i use it?
I have searched other sites and books but not find any solution.

Thank you for your helps.

[josesanchez-hotmart]

Reading the tests, the callback works as a custom constraint you apply to find an element in the linked list; as a function, it should return true for the elements you want to find. Check here to see how it's used.

[halitaydin]

Thank you Jose, now everything is clear.