In Swift, the decision to use structs over classes depends on several factors related to the nature of the data and the desired behavior of the objects. Here are the key scenarios where you should prefer using structs over classes:
1. Value Semantics
Structs are value types, meaning each instance keeps a unique copy of its data. When you assign or pass a struct, you get a copy of the data, ensuring that changes to one instance do not affect others. This is particularly useful when you want to ensure data immutability and avoid unintended side effects.
2. Simple Data Types
Structs are ideal for simple data types that represent well-defined, self-contained values. Examples include database objects like NewsItem, Task, or User[1][2]. These types often do not require complex relationships or behaviors that necessitate reference semantics.
3. Thread Safety
In a multi-threaded environment, structs are inherently safer because they are copied when passed between threads, eliminating the risk of race conditions or deadlocks that can occur with shared references in classes[1][2][4].
4. No Need for Inheritance
Structs do not support inheritance, so they are suitable when you do not need to create a class hierarchy. Instead, structs can conform to protocols and be extended, providing flexibility without the complexity of inheritance[1][2][5].
5. Predictable Data Manipulation
With structs, data manipulation is more predictable. Modifying a struct results in a distinct copy, ensuring the original data remains unchanged. This is beneficial when handling data that should not be inadvertently altered[1].
6. Performance Benefits
Structs can be more performant than classes, especially for small, simple data types. They are allocated on the stack, which can be faster than heap allocation used by classes. Additionally, structs do not involve reference counting, reducing overhead[1][4].
7. Mostly Value Types
When the properties of a struct are mostly value types (e.g., String, Int), it makes sense to use a struct. This ensures that the entire object maintains value semantics, making the code easier to reason about[1][2].
8. Copy-on-Write Optimization
Swift's copy-on-write optimization for structs ensures that copies are only made when necessary, which can mitigate pe...
