DevPrep

All topics › Memory management

When can you skip [weak self] in a closure?

Middle PRO

Rule

[weak self] is needed when a cycle forms: self stores the closure (directly or through an object it holds) and the closure captures self. If there is no cycle, a strong capture is safe and often preferable: it merely extends self's life until the work finishes.

The rest of this answer, with code and interview follow-ups, is in the DevPrep app.

Read the full answer in DevPrep

Practice this before your interview

DevPrep turns these answers into one-minute challenges: what does this code print, find the bug, mock interviews. One challenge a day.

Get DevPrep on the App Store