Why does declaring a collection with let in Swift NOT prevent modification of its contents, even if the collection is a class instance?

hard📝 Conceptual Q10 of 15

Swift - Collections

Why does declaring a collection with let in Swift NOT prevent modification of its contents, even if the collection is a class instance?

ABecause <code>let</code> makes the reference constant, not the object itself

BBecause Swift copies the collection on declaration with let

CBecause <code>let</code> disables all methods on the collection

DBecause collections declared with let are automatically frozen

Step-by-Step Solution

Solution:

Step 1: Understand what let does in Swift
let makes the variable reference constant, meaning it cannot point to a different object.
Step 2: Recognize difference between reference and object mutability
If the collection is a class instance, its internal state can still change unless the class restricts it.
Final Answer:
Because let makes the reference constant, not the object itself -> Option A
Quick Check:
let affects reference, not object mutability [OK]

Quick Trick: let fixes reference; object mutability depends on type [OK]

Common Mistakes:

Master "Collections" in Swift

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

More Swift Quizzes