Scuffing it off a little harder, Kotlin seems to get around Java in coming times!
Android smartphones have been backed up by several smartphone manufacturers – Sony, Samsung, HTC, Lenovo, Micromax, MI etc. which have all built phones designed specifically for the Android System. This has specifically aided Android significantly in gaining market share.
The Android operating system is projected to account for almost 60 percent of the global tablet operating system market share by 2020.
The popularity of Android devices has directly impacted Google Play app store which was earlier launched as Android Market. It is the biggest app store with around 3.6 million apps available for download, according to Statista.
Must-Know Tools Required For Android Developer
Java – An Android developer must master the fundamentals of Java programming language. They must be aware of data structures, algorithms, design patterns, testing and debugging and programming best practices.
SQL – It is important to have basic knowledge of SQL to organize the database in Android Apps. SQL is required to query the database (insert, modify, delete and drop records)
Android Software Development Kit (SDK) and Android Studio – Android Studio is the officially integrated development environment (IDE) for Android App Development. Developers write code with help of Android packages and libraries.
In addition to this, another good reason to develop Android Apps is the ease of processing apps on the Google Play Store is simple and satisfying.
XML – Basics of XML are important in designing user interface, parsing data feeds etc. XML storage is independent of platform. It can be used to structure the documents (for outsourcing data rather than integrating into HTML documents).
Understanding Kotlin As A Successor Of Java
Kotlin first appeared in 2011. It was designed to be an open-source, general-purpose programming language that is statistically typed, has a type interface and is made to work across platforms. JetBrains and its contributors have been on it since 2011, under license from Apache.
Kotlin for Native interface has reached its beta version with Kotlin 1.3. Kotlin is concise – It can reduce the boilerplate code to a great extent. It helps declare one-line functions, simple structs/JavaBeans in one line. Get and Set can be declared, data annotation can be added to the class, that ultimately triggers autogeneration of hashCode, toString, and other boilerplate equals.
It is safe- in a way that an entire class of error can be avoided by making use of null pointer exception. With Kotlin existing libraries can be leveraged for the JVM, Android and the browser.
Example of Simplest Version of Kotlin
Package hello
Fun main()
{
Println (“Hello”)
}
An object-oriented version of the above example:
class Greeter(Val name: String) {
fun greet() {
println(“Hello, $name”)
}
}
fun main(args: Array<String>) {
Greeter(args[0]).greet()
}
Example of Coroutine:
suspend fun main() = coroutineScope {
for(i in 0 until 10) {
launch {
delay(1000L – i * 10)
print(“How are you? “)
}
}
}
What good does Kotlin bring?
Kotlin comes as a fresh respite for those who struggle with issues that Java has been long dealing with. These include:
- A type system that has been controlling null references
- The absence of raw types
- The absence of proper function types (SAM Conversions)
- Lack of invariant arrays
- Presence of checked exceptions
- Java makes use of site variance without wildcards
Kotlin has eased the world for Android developers as it comes with some new features, which Java does not have:
A combination of lambda expressions and inline functions makes Kotlin, performant custom control structure
It comes along with extension functions, null safety feature, smart casts, string templates, primary constructors, first-class delegation, type interface for variable property types, singletons, type projections, declaration-site variance, operator overloading, companion objects, data classes, separate interfaces for reading only and mutable collections, co-routines.
With all these features and more, Kotlin is being used in the majority of sectors which includes its applications in mobile app development. It has quickly gained control over the USP’s of Java, the presence of Checked exceptions, the presence of Primitive types that are not classes, excessive usage of Static members, the occurrence of Non-private fields, interruptions by Wildcard-types, and use of Ternary-operator a? b: c.
Kotlin looks like Java and behaves like C and C++. There is no requirement to explicitly declare and initialize variables before they are used in Kotlin. It, as well, supports procedural and objects oriented programming as in Java. So what is it that differentiates Kotlin from Java, if everything looks and behaves in the same way with both these programming languages? Have a look at some quick pointers here:
- JVM Bytecode or JavaScript is the outcome of a compilation of Kotlin
- Kotlin programs can make use of all existing frameworks and libraries.
- It has a clean syntax and can be learned easily.
- It costs nothing as it is open source.
- Java can easily be converted into Kotlin, or both codes can be written simultaneously without misleading the syntax. A native java developer can learn Kotlin with very fewer efforts.
- Null pointer exceptions can easily be avoided as Kotlin simply refuses to compile code that tries to assign or return Null. But in cases where we have to make use of Nullable types, we have to make use of “?” after the variable type.
- Kotlin focuses on readable syntax, therefore, code reviews are not a problem for those who are not familiar with the language.
Some Amazing Kotlin Features to look forward in 2019
Null Safety
Thus Kotlin secures the code from data classes, null safety, functional concepts, and operator overloading. Apart from these extension functions, smart casts are some other features to be considered
Collections and Streams
Users new to Kotlin have to beware of lazy initializations and Java Stream API’s. In this regard, Kotlin’s API’s Collection is very expressive and versatile. But the design might seem tedious. To ease this out, the Stream API abstraction had to be introduced.
Named Parameters
Kotlin permits passing default values to parameters in the function definition.
Extension Functions
Kotlin programming language offers certain useful Standard Library Functions – that extends the idea of introducing new functionalities into an existing class when that particular class is expanding and that might be the case always. Kotlin comes up with powerful standard extension functions to add new functionalities to the existing classes easily.
Immutability
Kotlin features immutability, to ignore the side effects caused by the functions. Immutability implies, an object/variable once created cannot be changed. Therefore in case properties of that object have to be changed, it is required to clone the entire object/variable. Cloning in Java simply chews off the memory and looks verbose and wrong. Why Kotlin makes use of immutability is because it is threaded safe, there are no race conditions, no concurrency problems and there is no need to sync.
Normally there are two main threads in Android (UI and background) – that work independently if we try to write clean code. Java only offers a limited amount of support to ensure that the software is immutable during the time of compilation. Kotlin provides high-end compiler support that is able to distinguish between properties and values that are immutable.
String Interpolation
Strings are difficult to handle in Java, and many operators like plus operators, StringBuffer and String.format() have to be used. But Kotlin erases all hassles by introducing String Interpolation.
How does a Kotlin compiler translate “Hello, $name!” by making use of
Java.lang.String.format (“Hello, $$!”, name) or is there some alternative solution?
If there is a class like this (as an example)
Class Client
{
Val firstName: String
Val lastName: String
Val full Name: String
Get()=”$firstName $lastName”
}
So the solution should be a cached string or is it going to build a new String?
Can we make use of “lazyof” delegates, instead of the above code?
The Kotlin compiler will translate the above code to:
newString Builder ().append (“Hello,”).append (name).append (“!”).toString ()
Therefore, no caching is performed. Each time you evaluate an expression containing a string template, the resulting string will be built again.
Singletons
An object in Kotlin only exists as a single instance in the program life cycle. It can further be used to create singletons as the feature is not limited. This concept is an extension of enums, interfaces, and classes that were available in Java programming language.
Sealed Classed and enumerations
Extending the concept of singletons and enumerations, abstract classes are well defined in Kotlin, which is not the case in Java Programming language. Sealed classes are used in creating enumerations along with flexible sub-classes, in which compiler ensures that only those classes that can be directly extended or nested in a sealed class are valid examples of enumeration.
Clamming Up
Kotlin is considered a more stable option for Android Studio and is built to improve existing Java models by offering extensive solutions to API design deficiencies. Top Android App Development Firms prefer Kotlin because of its simplicity in comparison to Java programming language. Kotlin code is easy and mixing and merging it along with Java, also makes huge sense, as top Java Developers can easily learn Kotlin and imbibe it within their basics.