Use of Swift Generics In IOS Mobile App Development

Generics in Swift

IOS Mobile App Development  In swift, Generics are the parameterized types. By using generics, we can write clear, flexible and reusable functions. It allows us to avoid duplication of functions, and lets we write our code in a clear and expressive manner. Swift is a strong-typed language and that means that when we define a type for a variable – we always must do that – we can’t change it later. Neither can this variable contain different types, because it can only have one type. With generics we can specify a “generic type” – a type that’s loosely defined and for instance constrained by its relation to other variable types. Generally, in swift by using generics we can avoid a duplicate code by writing a reusable functions or methods in a clear and abstracted manner based on our requirements.

The concept of generics is powerful in swift and the standard libraries like arrays or dictionaries of swift built by using generic code. In swift, when we create an array, it can hold any type of data like integer, string or any other types same way dictionaries are also used to hold any type of data as a key value pair.

The simple non-generic function example which shows how generics will help in swift programming

language.

In above example we defined a two functions intValueSwap, stringValueSwap to swap integers and strings separately because intValueSwap function will work only for Integers value and stringValueSwap function will work only for Strings. So, if we use non-generic code we need to create a separate methods or functions based on the type of data due to that redundant code will increase in application.

Generic Functions

We define a generic function by using angle brackets with a type placeholder after the function name. The convention is for this placeholder to be called T.

In this example we define a function that does nothing except return the parameter that is passed to it. By adding <T> after the function name we’ve indicated that this is a generic function and that used T as a placeholder for the type. In the functions type signature, we have indicated that it takes a parameter called x of type T and returns something of type T.

We can call this function with an integer, Double or a string and it works with either one.

Now we will implement a generic version for the above example which we used to swap integers and strings.

The example of using generics to avoid a redundant code in swift programming language.

Conclusion

That’s it. So far we have covered the basics of generics and generic functions, In the next blog we will cover Generic as a type, Extension, Associated type and generic with where clause so on.

Author

Pankaj Ray

Canarys Automations PVT LTD