Skip to main content

How to Replace Switch with When in Kotlin?

As a beginner, you might look for how the Kotlin switch statement works. If your background is working in C, Java, etc. then switching to Kotlin works best. There is no switch statement available in Kotlin; instead, it replaces the switch with the when expression.

The switch is used as a two-state user interface element and work as a toggle between ON and OFF like button. One can add a switch into our application layout by using its switch object. By default, the switch is off. Moving on with Kotlin, then When is replace the Switch operator. A specific block of code needs to execute when the condition fulfilled. One can take help from Kotlin App Developers and develop android application.

In Kotlin switch case with string, when is mainly used in two ways:

  • When as a statement
  • When as an expression

When’ is an expression compared with other branches. If it used as a statement, the branch values compared sequentially with the argument and execute the corresponding branch where the condition matches. Here in this blog, we’ll look at how switch replaces the when.

Let’s start with understanding Switch in Kotlin Android and then we’ll check how the when keyword makes our code easier and more understandable.

Switch

Suppose you have used a conditional statement where the condition used in the conditional statement applies to a similar type of data. Then instead of that use vast code for the conditional statement. Use the switch to avoid using too many conditional statements in our code. Let’s study with the help of an example.

Let’s consider one example where we have to return emoji based on input spring.

input spring.
But if we rewrite the code using the When statement in Kotlin, then it provides better readability than if/else. In the above code, if/else statement replaced with the when statement.

fun getthe emoji

Replace Switch Case Kotlin with When

Replace Switch Case Kotlin with When

Similar to if/else, the switch is one of the ancient ways to deal with conditional execution. Whereas in Kotlin, we can replace switch case and if/else with when similarly, we implement the conditional execution. Now the switch can replace with the when statement also to if/else. Make the code more readable, consistent and adapt quickly with new developers.

Return values with When Block

Till now, you have seen the ability of when the block in Kotlin switch case with spring replaces conditional statements. But well, it can do more than this. Let’s say, it can return the values from the conditional blocks after you execute the necessary steps.

Return values with When Block

Arbitrary Condition with When

We can also use more than one checks to execute a block when the operator

Arbitrary Condition with When
There are several causes, but only one case that matches up will work as a respective block of code that executed. The comma added in the above example act as an OR operator.

Using When without an Argument

Using When without an Argument

We’ve used ‘when’ with an argument. But when the real potential of when is we use when without an argument. Understand how it looks.

Later, it acts as an if/else block with class-level variable conditions.

Now, Compare the instance with When

We can check whether the given operator is an instance of a particular type at runtime by using the ‘is’ operator. The operator ‘is’ works similar to the instanceof operator in Java. Now use the ‘is’ and ‘!is’ operator inside when block. Get to know how Kotlin switch case with string works with an example.

Now, Compare the instance with When

Main points about Kotlin when

Java uses Switch conditional statements that operated with primitive data types, string class, and Kotlin switch enums. instead, Kotlin allows when to be used with any user-defined types. It makes it developer-friendly.

Unlike Java, Kotlin’s when can use with dynamic value like return type of functions.
Also, check whether the given argument in collections uses the ‘in’ operator, which acts as contains.

The else is mandatory if you’re using when as an expression.

Example of a wide range of utility functions

In Kotlin, few simple utility functions are used for a simple task. Let’s say if you want to get a minimum or maximum value in the range. Similarly, the average value of the sum of range, total count or value of the range, etc.

Check below Kotlin Functions

  • count()
  • average()
  • min()
  • max()
  • sum()

Summary

In this blog, we have seen how powerful and useful the kotlin when the expression is. If you’re using Kotlin, you find yourself using the when expression all the time. Connect with us if you’re seeking to Hire Kotlin App Developers and switch to Kotlin when.

Comments

Popular posts from this blog

How Much Does It Cost To Hire An App Developer In 2019?

It is considered a very important question that how much it effectively costs for the purpose of hiring an app developer and that too in the year 2019. Nowadays, due to the rising trend, it is very important to hire iPhone developer. Also, it seems that each business, as well as every brand, has its own app in the year 2019. In that way, you can also hire iPhone app developer India. Even, there are many of the local coffee shops which possess an app for the purpose of ordering a frappuccino available at your doorstep or you can collect it on discounts. For developing these apps, sometimes it becomes very important to preferably hire iPhone programmer. There is a gradual presence of many of the IT entrepreneur who is usually making a fortune from a hit app. So, here are given some of the ever-actual issues of how to  hire iPhone app developer  for the development purpose. We will preferably talk about some of the important as well as general tips which can prove helpful to hire io

Engagement Models For Laravel Application Development

  In the mobile app, the development backend holds prime importance. It has a trusted and dependable technology that would take good care of your backend operations with ease. For this purpose, Laravel creator said, “we want to simplify the development process”. Today the Laravel 5.4 is the latest released version that enforces the same ideology with new features. Leverage the best Laravel application development service & create a well-tailored web app. Hire a Laravel development company to scale business growth. Laravel provides predefined architecture and customized backend logic to stand out differently from the crowd. Hire Laravel developers in India and choose the company that understands your needs. We are one of the best leading web application development companies in India. We offer a wide range of engagement models that suits our customer’s needs. Let’s dive into understanding the engagement models in a better way. What are engagement models? An engagement model is a

5 Features while Developing On-Demand ‘Mover n Packers’ App like Uber Movers

Peeping into a few years back, though there were mobiles trending, mobile apps were more limited towards messaging and gaming, but a year or two year back scenario depicts a different story in all. On-demand applications that can be for Food or say Cab Booking or for Salon or for the  Guard booking app  for the event, anything, and everything can be covered in the app itself. UBER is considered more of as a BRAND instead of just an app to book the cab. It has widespread its scope beyond the app in various fields across the globe. Along with the services of moving human from one destination to another, not just limiting to that, Uber is even into Movers and Packers, namely Uber Movers. According to the report, “UberMovers provides free and professional moving services for up to ½ an hour for students in Atlanta between 9 a.m. to 2 p.m. on Saturdays only”. Similar moving services, it provides in Nashville even. Eventually, it is spreading its wings further too. Are you the one prov