Which mechanism underpins the performance optimisation for many Swift value types such as Array, when multiple copies appear but actual duplication is delayed until needed?

Problem Statement

Explanation

Many Swift value types (e.g., Array, Dictionary) use Copy on Write (COW) under the hood: multiple variables may share storage until a mutation forces duplication, improving performance while preserving value semantics. This detail is often asked in interviews.

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This question appears in the following practice sets:

Structs, Classes & Value vs Reference Types

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Which mechanism underpins the performance optimisation for many Swift value types such as Array, when multiple copies appear but actual duplication is delayed until needed?

Problem Statement

Explanation

Practice Sets

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Master Interviews Anywhere, Anytime

Which mechanism underpins the performance optimisation for many Swift value types such as Array, when multiple copies appear but actual duplication is delayed until needed?

Problem Statement

Explanation

Practice Sets

Related Questions

What is the difference between `let` and `var` in Swift?

What does the `?` after a type name signify in Swift, e.g., `Int?`?

Which statement is true about `struct` vs `class` in Swift?

What is the purpose of a `guard` statement in Swift?

Which of these best describes a closure in Swift?

More from Swift

Master Interviews
Anywhere, Anytime