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Swift Programming Tutorial: Weak References
Understand That ‘weak’ in Swift Isn’t Really Weak at All
The mighty yet misunderstood weak! It’s one of those words in Swift that seems unassuming but wields great power, like a wizard whispering magic to avoid memory leaks.
This article is part of my Swift Programming Tutorial series.
What is weak in Swift?
When you declare a property as weak, you’re telling Swift, “Hey, I don’t want this property to own the thing it’s pointing to. I just want to borrow it and let someone else keep the main responsibility for it.”
Here’s the deal: Swift uses ARC (Automatic Reference Counting) to manage memory. Objects can have strong references to each other, which means, “I own you, and I won’t let you go!” But if two objects own each other at the same time, it’s like a clingy couple — neither one lets the other go, and they’re stuck in memory forever. This is called a retain cycle, and it’s bad news.
Enter weak, the hero that saves the day by breaking this cycle. A weak reference doesn’t increase the reference count of the object it points to, so the object can still be deallocated when the strong references let it go.
