Value Types and Reference Types in Swift

We can categorise types into two main groups: Value types and Reference types in Swift. The distinction between them is crucial because it affects how data is managed, copied, and passed around in your code.

1. Value Types:

Examples: Structs and Enums

Characteristics:

•  Instances of value types are copied when they are assigned to a new constant or variable, or when they are passed as arguments to functions or methods.
• Each instance of a value type has its own copy of the data.
• Changes to one instance do not affect other instances.
• Immutability can be easily achieved by using the let keyword.

When to Use:

• For small, simple data types that don’t have a complex lifecycle.
• When you want a copy of the data to be independent of the original.

Example of a value type (struct):

struct Point {
    var x, y: Int
}

2. Reference Types:

Examples: Classes, Closures

Characteristics:

• Instances of reference types are not copied when they are assigned to a new constant or variable or when they are passed as arguments to functions or methods. Instead, a reference to the same instance is used.
• All references point to the same instance, so changes made to the instance affect all references to it.
• Reference types have a more complex lifecycle, including issues like retain cycles.

• For larger, more complex data types that have a more intricate lifecycle.
• When you want changes to one instance to be reflected in all references to that instance.

class Person {
  var name: String
    init(name: String) {
    self.name = name
  }
}