What is the difference between class and structure in Swift?

 

The Main difference in Class and Structure 

        Classes are reference types. Structures are value types. Classes have an inheritance that allows one class to inherit the characteristics of another. Structures do not support inheritance.

Class ( Reference Types )

• Reference Type
• When you copy a reference type, each instance shares the data. The reference itself is copied, but not the data it references. When you change one, the other changes too.
• Inheritance
• Classes have an inheritance that allows one class to inherit the characteristics of another.
• Initializer
• We have to define the initializer manually.
• Storage
• Class instances are stored on the heap.
• Thread Safe
• Classes are not fully thread−safe.

Example : 

 
class EmployeeList {
    
    var name: String
    var age: Int
    
    init(name: String, age: Int) {
        self.name = name
        self.grade = grade
    }
}

let emp1 = EmployeeList(name: "Dixit Akabari", age: 27)
let emp2 = emp1
emp2.name = "Ms Dhoni"

print("emp1 name: \(emp1.name)")
print("emp2 name: \(emp2.name)")

OutPut :

    emp1 name: Ms Dhoni
    emp2 name: Ms Dhoni

Structure ( Value types )

• Reference Type
• When you copy a value type each instance keeps a unique copy of the data. If you change one instance, the other doesn’t change too.
• Inheritance
• Classes have an inheritance that allows one class to inherit the characteristics of another.
• Initializer
• We have to define the initializer manually.
• Storage
• Class instances are stored on the heap.
• Thread Safe
• Classes are not fully thread−safe.

Example : 

struct EmployeeListStruct {
   var name: String
   var age: Int
}

let emp1 = EmployeeListStruct(name: "Dixit Akabari", age: 8)
var emp2 = emp1
emp2.name = "MS Dhoni"

print("Employee1 name: \(emp1.name)")
print("Employee2 name: \(emp2.name)")

OutPut :

    Employee1 name: Dixit Akabari
    Employee2 name: MS Dhoni

Conclusion

        Now Hopefully, you’ll be easier to reason about choosing between a class or a struct.