Kotlin PPT Points

Why Kotlin

1. Null Safety: Kotlin has built-in null safety features, which help prevent null pointer exceptions at compile time. This is achieved through nullable and non-nullable types, reducing the risk of crashes caused by null references.
2. Interoperability: Kotlin is fully interoperable with Java, meaning you can use Kotlin code alongside Java in the same project. This allows for a smooth transition for teams already working with Java or for integrating Kotlin into existing Java projects.
3. Extension Functions: Kotlin allows developers to extend existing classes with new functionality without inheriting from them. This is done through extension functions, which can enhance the readability and maintainability of code.
4. Coroutines: Kotlin provides first-class support for coroutines, which are a lightweight concurrency design pattern. Coroutines simplify asynchronous programming by allowing developers to write asynchronous code in a sequential style, making it easier to understand and maintain.
5. Immutable Data: Kotlin encourages immutability by making it easy to define immutable data structures using the val keyword. This can lead to safer and more predictable code, especially in multi-threaded environments.
6. Smart Casts: Kotlin’s smart casts allow for the automatic casting of types within conditional blocks, eliminating the need for explicit casting and making the code more concise and readable.
7. Conciseness: Kotlin requires less boilerplate code compared to Java. It has features like type inference, data classes, and extension functions that allow developers to write more expressive code with fewer lines.

Kotlin: A Statically-Typed Language

• How it’s a statically typed language. when we create a variable in Kotlin, we also say what type of data it will hold, like numbers or text.
• before we run our code, Kotlin checks to make sure we’re using the right types in the right places.
• Kotlin has different types of data it understands, like numbers, words, and true/false values.
• It can also understand custom types created by us.
• One cool thing about Kotlin is. It can figure out the type of data we are using without us needing to tell it explicitly.
• This makes our code shorter and easier to read.
• With the help of this feature, kotlin helps us avoid a common mistake called a NullPointerException at the compile time.
• This happens when our code tries to use data that doesn’t exist. Kotlin’s static typing system helps us catch these mistakes before our code even runs.
• Overall, Kotlin’s static typing makes our code safer, and easier, and less errors. That’s why many developers love using Kotlin for their projects.

Kotlin is 100 interoperable with Java programming language, allowing developers to leverage existing Java libraries and framework

• Kotlin and Java can be best friends in programming. When we say they work together, it means we can use all the cool stuff we already have in Java with our Kotlin projects.
• If there’s a useful tool or code library in Java that we want to use in our Kotlin project, we can do that without any problems.
• When we write Kotlin code, we can use Java’s classes, and methods.
• And if we have some Kotlin code that we want to use in a Java project, we can do it very easily!
• So whether you’re already comfortable with Java or you’re just starting to explore Kotlin, they can work together smoothly giving you a lot of flexibility and options in your projects.

You can have java and kotlin code in one project

• putting Java and Kotlin in the same project. It’s like having chocolate and vanilla ice cream together!
• When you mix Java and Kotlin, it’s like having two sets of tools in your toolbox. You can use whichever tool works best for the job you’re doing.
• If you’re already working on a project in Java but want to start using Kotlin, you can just add a Kotlin file to the Java project.
• You just need to install Kotlin plugin inside the java project.
• It’s also really handy if you’re learning Kotlin but still want to use some of your old Java code. You can use them together without any problems.
• Mixing Java and Kotlin gives you the best result and flexibility. You get to use all the cool stuff from both languages.
• So if you are a professional Java developer, still you can use kotlin in your project and you can use some useful features of kotlin by mixing both.

Officially announced in 2011 and later open source in 2012

• Kotlin is developed by JetBrains, and they’re always working hard to improve it. With each new version of Kotlin, they fix bugs, add new features, and make the language even more efficient.
• Kotlin was Officially announced in 2011, and later in 2012, they were announced as open source.
• JetBrains also listens to feedback from developers and fixes any issues or bugs that pop up. This way, Kotlin keeps getting better and better with each release.
• 1.9.22 is the latest and most stable version of Kotlin.

Kotlin Multiplatform

• Kotlin Multiplatform is a feature that allows developers to share code across multiple platforms, such as Android, iOS, web, and desktop.
• With Kotlin Multiplatform, developers can write common code that can be shared between platforms like Android, iOS, web applications, and even desktop applications.
• This means less code duplication and more efficient development.
• Instead of writing separate code for each platform, developers can write shared code in Kotlin and then customize platform-specific code where needed.
• One of the best things about Kotlin Multiplatform is that it’s not limited to just mobile development.
• You can use it for web development, backend services, and even IoT (Internet of Things) projects.

Kotlin Coroutines

• Kotlin Coroutines are a way to write asynchronous, non-blocking code simply and efficiently.
• One of the best things about Kotlin Coroutines is. Instead of dealing with complex callbacks or threads, you can write asynchronous code that looks and feels like regular sequential code.
• Coroutines are lightweight, which means they don’t consume a lot of resources.
• Kotlin Coroutines also comes with built-in support for cancellation and error handling, making it easier to write robust and reliable code.
• Whether you’re writing code for Android apps, backend services, or desktop applications, Kotlin Coroutines can help you write faster, more responsive code that’s easier to understand and maintain.

Kotlin Extension Functions

• Extension functions allow you to add new functionality to existing classes without modifying their source code.
• Inside the function, you can use this to refer to the instance of the class
• Extension functions promote code reusability and readability by allowing you to extend the functionality of classes without modifying their source code.

Lambdas in Kotlin

• Kotlin also supports lambdas same as the Java 8 feature.
• So I’ll not talk more about it, because we already know lambda in Java.
• Using Lambdas, you can write code that’s more declarative and expressive. Instead of writing long, procedural code.
• Whether you’re writing backend services, Lambdas in Kotlin can help you write cleaner, more elegant code that’s easier to understand and maintain.

Optional Semicolons in Kotlin

• In Kotlin, you don’t have to use semicolons, which makes the code look cleaner and simpler.
• Unlike some other languages where semicolons are required to end statements. But in Kotlin it’s your choice.
• whether you’re a fan of semicolons or not, Kotlin gives you the freedom to choose.
• We are Java developers and we are the biggest fans of semicolons.

Class Headers in Kotlin

• A class in Kotlin has a primary constructor and possibly one or more secondary constructors. The primary constructor is declared in the class header, and it goes after the class name and optional type parameters.
• Primary constructors are part of the class header and define how instances of the class are created.
• Primary constructors allow the initialization of class properties directly from the constructor parameters, reducing boilerplate code.
• Primary constructors provide flexibility in defining class properties and initializing them during object creation.

String Template

• String templates in Kotlin allow you to directly insert variables or expressions into strings without concatenation.
• Use a dollar sign ($) followed by curly braces {} to insert variables or expressions.
• They make string concatenation easier and cleaner compared to traditional methods.
• You can also put expressions inside the curly braces to perform calculations or call functions directly within the string.
• Kotlin supports multi-line strings using triple quotes (“””), which work with string templates.
• Example: "The result of adding ${a} and ${b} is ${a + b}".

Default parameter value

• Default parameter values allow you to specify default values for function parameters in Kotlin.
• When declaring a function, you can assign default values to parameters directly in the function using the assignment operator (=).
• Default parameter values make functions more flexible by allowing you to call them without providing values for all parameters.
• If a parameter is not provided, the default value is used.
• You can override default parameter values by providing explicit values when calling the function.

When Expression

• The “when” expression in Kotlin is similar to the switch statement in other languages, but it’s more powerful and flexible.
• The “when” expression is like a super flexible tool that helps you handle different situations easily.
• You can use “when” to check not just values, but also the type of something.
• Multiple conditions can be combined in a single branch.
• Unlike switch statements, “when” expressions in Kotlin don’t have fall-through behavior. Once a branch is matched, the execution exits the “when” block, which helps in writing more bug-free code.
• The “else” branch handles cases where none of the conditions match.

Ranges and Progressions in Kotlin

• Ranges are Represent sequences of values from a start point to an end point.
• Ranges Created using the “..” operator.
• Progressions are Sequences of numbers following a pattern or step.
• Progressions Created using the “step” function on ranges or “downTo” for decreasing sequences.
• Ranges and progressions can be iterated over using loops or higher-order functions.
• Commonly used in loops for iterating over sequences of numbers or characters.

Smart Casting in Kotlin

• Smart casting is a feature in Kotlin that allows the automatic casting of a variable to a more specific type within a certain scope.
• Smart casting is particularly useful when working with nullable types
• Smart casting works with both simple type checks (using the ‘is’ operator) and ‘when’ expressions.
• Kotlin provides functions like ‘as?’, ‘as’, ‘as!’, and ‘let’ to perform safe casts and handle nullable types effectively.
• Smart casting simplifies code by null checks
• smart casting is powerful because it avoids runtime exceptions.

DSL in Kotlin

• A DSL is a special language for one thing, making it easier to talk about and solve problems related to that thing.
• Kotlin HTML Builder is a library in Kotlin that helps make HTML code with a special easy way to write it.
• Anko is also library in Kotlin for making Android apps. It has a special way of writing code for making app layouts and handling things like buttons.