Structs are value types (copy on assign) in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean that structs are value types in Swift?

It means when you assign a struct to a new variable or pass it to a function, Swift makes a copy of the struct instead of sharing the same instance.

beginner

How does assigning one struct variable to another affect their data?

Each variable gets its own separate copy of the data. Changing one does not affect the other.

intermediate

Compare structs and classes in Swift regarding assignment behavior.

Structs are value types and are copied on assignment. Classes are reference types and share the same instance when assigned.

intermediate

Why might Swift use value types like structs for some data?

Value types help avoid unexpected changes because each copy is independent. This makes code safer and easier to understand.

beginner

If you change a property of a struct after assigning it to another variable, what happens?

Only the struct you changed is affected. The other variable still has the original data because it has its own copy.

What happens when you assign a Swift struct to a new variable?

A A new copy of the struct is created.

B Both variables point to the same struct instance.

C The struct is converted to a class automatically.

D The original struct is deleted.

Structs are value types, so assignment creates a new copy.

If you modify a struct after assigning it to another variable, what happens to the other variable?

A It stays the same because each variable has its own copy.

B It also changes because they share the same data.

C It becomes nil automatically.

D It throws a runtime error.

Each struct variable holds its own copy, so changes do not affect others.

Which of these is a reference type in Swift?

A Enum

B Struct

C Class

D Tuple

Classes are reference types; structs, enums, and tuples are value types.

Why are structs considered safer for some data than classes?

A Because they use less memory.

B Because they are copied on assignment, avoiding shared state bugs.

C Because they can inherit from other structs.

D Because they run faster than classes.

Copying on assignment prevents unexpected changes from shared references.

Which keyword defines a struct in Swift?

A class

B enum

C value

D struct

The keyword 'struct' is used to define a struct in Swift.

Explain in your own words what it means that structs are value types and how assignment works.

Think about what happens when you give a copy of a drawing to a friend.

Describe the difference between structs and classes in Swift regarding how they handle data when assigned to new variables.

Imagine copying a photo versus sharing a link to the photo.