Java:
Java is a general-purpose programming language that is class-based, object-oriented, and designed to have as few implementation dependencies as possible. It is intended to let application developers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation
Kotlin:
Kotlin is a cross-platform, statically typed, general-purpose programming language with type inference. Kotlin is designed to interoperate fully with Java, and the JVM version of its standard library depends on the Java Class Library, but type inference allows its syntax to be more concise.
Kotlin vs Java
- Java compilation time is 15-20% faster than Kotlin compilation time but in perspective of incremental build compilation, Kotlin will also take same compilation time as Java Online Training.
- In Kotlin, we can’t assign null values to variables or return values, if we really want to assign then we can declare a variable with special syntax whereas in Java we can assign null values but when we try to access objects pointing to null values raises an exception.
Code Conciseness
- Comparing a Java class with an equivalent Kotlin class demonstrates the conciseness of Kotlin code. For performing the same operation that the Java class does, a Kotlin class necessitates for less code.
- For example, a particular segment where Kotlin can significantly reduce the total amount of boilerplate code is findViewByIds.
- Kotlin Android Extensions permit importing a reference to a View into the Activity file. This allows for working with that View as if it was part of the Activity.
Coroutines
- CPU-intensive work and network I/O are long-running operations. The calling thread is blocked until the whole operation completes. As Android is single-threaded by default, an app’s UI gets completely frozen as soon as the main thread is blocked.
- The traditional solution for the problem in Java is to create a background thread for the long-running or intensive work. However, managing multiple threads leads to an increase in the complexity as well as errors in the code.
- Kotlin also allows the creation of additional threads. However, there is a better way of managing intensive operations in Kotlin, known as coroutines. Coroutines are stackless, which means they demand lower memory usage as compared to threads.
- Coroutines are able to perform long-running and intensive tasks by suspending execution without blocking the thread and then resuming the execution at some later time. It allows the creation of non-blocking asynchronous code that appears to be synchronous.
- The code using coroutines is not only clear but concise too. Moreover, coroutines allow for creating elegant additional styles of asynchronous non-block programming such as async/await.
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Extension Functions
Kotlin allows developers to extend a class with new functionality via extension functions. These functions, although available in other programming languages like C#, aren’t available in Java.
Creating an extension function is easy in Kotlin. It is done by prefixing the name of the class that needs to be extended to the name of the function being created. In order to call the function on the instances of the extended class, one needs to use the ‘.’ notation.
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