In Kotlin, scope functions allow you to execute a function, i.e. .also () .let () .apply () .run () They are magical because they can perform some Kotlin magics and at the same time greatly resemble English words. In order to avoid ambiguity, Kotlin has the so-called use-site target declaration. If you liked this tutorial, please share it Comment below with any questions or issues you faced. They are magical because they can perform some Kotlin magics and at the same time greatly resemble English words. Whereas run, and with can be used as a normal function as well. The %useLatestDescriptors line magic will force Kotlin Kernel to pull and apply the latest repository version of all library descriptors. Those of us who have used Kotlin for development have most likely encountered the set of useful functions from Standard.kt. In the first lambda, we append the string “Dog Park!”, this value is returned from the lambda and pushed into the second lambda. You probably already heard about them and it's also likely that you even used some of them yet. I hope all of you know these are Kotlin standard scope functions which are used to run a block of code with a context and return the result. The Kotlin Programming Language. Using them can increase readability and make your code more concise. 4.1. Each of these functions takes a lambda as a parameter – an easy way to think of a lambda is to think of it as an anonymous function that … Weiter bringt Kotlin viele Dinge von Haus aus mit… Let's assume Apply is a person name, I can make a grammatically correct English sentence with them: it also let Apply run. Browse content geared toward a range of skill levels, from student to professional. A really simple of this is to manipulate a String. Run your code from IntelliJ IDEA. Native. Each of these functions takes a lambda as a parameter – an easy way to think of a lambda is to think of it as an anonymous function that affects the original object. Ktor Data Layer. It runs on the object reference (also known as receiver) into the expression and returns the object reference on completion. TL;DR obj.let{it}, obj.run{this}, with(obj){this} - returns result of last line obj.also{it}, obj.apply{this} - returns the same object. Make sure to use the null-safe ?.syntax to call the trailing function. Join in, grow your skills through tutorials and discussion. COVID-19 - data, chart, information & news. Run the packaged application. If so, we call a User-scoped function to setReady() on the human. Super-useful for conversions: val person = Person ("Edmund", 42) val result = person. Build and package the application. There are two main differences between each scope function: 1. when we use the above functions, you can use the object within the block and returns the same object(this), Learning Android Development in 2018 [Beginner’s Edition], Google just terminated our start-up Google Play Publisher Account on Christmas day, A Beginner’s Guide to Setting up OpenCV Android Library on Android Studio, Android Networking in 2019 — Retrofit with Kotlin’s Coroutines, REST API on Android Made Simple or: How I Learned to Stop Worrying and Love the RxJava, Android Tools Attributes — Hidden Gems of Android Studio. let. You can follow any responses to this entry through RSS 2.0 . Now we may face a problem if the annotation requires a field to be public, for example, with JUnit’s @Rule annotation. This feels really awkward to use because it is syntactically different than the rest of standard functions – so, we tend to avoid using it. I hope all of you know these are Kotlin standard scope functions which are used to run a block of code with a context and return the result. You probably have seen some of them in various tutorials or even used them already. All of these five functions basically do very similar things. We can chain these together as well; for our example, we will print the status of our canineUserhunger field and then manipulate the original object based on its state – when a dog is hungry, we feed them. Attempting an operation, I even tried forming sentence using them can increase readability and make your differently. Have seen some of them in various tutorials or even used them already avoid ambiguity, Kotlin has the of. Receiver ) is affected depends on the result of the four supported build.. Classified based on the Receiver ) into the expression and returns result the. Sagen, dass eine Klasse in Kotlin, if we decorate a property with an annotation defined in Java... 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