Kotlin is known for his simplicity, and in our practice, more simplicity means more efficiency. In fact, a whopping 67 percent of professional Android developers who use Kotlin say it has helped them increase their productivity. In the next section, I’ll share some of the ways Kotlin helps our partner engineers become more productive and introduce you to the Kotlin features that can help.

A whopping 67 percent of professional Android developers who use Kotlin say it has helped them increase their productivity

Simple, simple and efficient

Kotlin’s simplicity has an impact at all stages of development:

  • As a code writer: You can focus on the problem you need to solve (not the syntax). Less code means less testing, less debugging, and less opportunity to write bugs.
  • As a reviewer and maintainer: You have less code to read, which makes it easier to understand what the code does, and therefore easier to review and maintain.

Here’s an example from the Flipkart team:

“In an internal survey, 50% of developers mentioned a reduction in the estimated time required to complete functionality for modules written with Kotlin.”

– it

Kotlin’s functionality and productivity

Because of Kotlin’s simplicity and high readability, most of Kotlin’s features can improve productivity. Let’s look at some of the most commonly used features.

Default parameters and builders

In the Java programming language, when some of the arguments in your constructor are optional, you usually do one of two things:

  • Add multiple constructors;
  • Implement the builder pattern.

With Kotlin, you don’t need to use either method because of the default parameter functionality. Default parameters allow you to override functions without additional boilerplate code.

Using Kotlin allowed the Cash App team to eliminate many builders, reducing the amount of code they had to write. In some cases, the amount of code was reduced by as much as 25 percent.

As an example, the following code shows how a Task object is implemented using the builder and the default parameters respectively. The only required argument for this Task is the Task name:

/* Copyright 2020 Google LLC. SPDX-License-Identifier: Apache-2.0 */ 3 - public class Task {-private final String name; - private final Date deadline; - private final TaskPriority priority; - private final boolean completed; - - private Task(String name, Date deadline, TaskPriority priority, boolean completed) { - this.name = name; - this.deadline = deadline; - this.priority = priority; - this.completed = completed; - } - - public static class Builder { - private final String name; - private Date deadline; - private TaskPriority priority; - private boolean completed; - - public Builder(String name) { - this.name = name; - } - - public Builder setDeadline(Date deadline) { - this.deadline = deadline; - return this; - } - - public Builder setPriority(TaskPriority priority) { - this.priority = priority; - return this; - } - - public Builder setCompleted(boolean completed) { - this.completed = completed; - return this; - } - - public Task build() { - return new Task(name, deadline, priority, completed); - } - } -} + data class Task( + val name: String, + val deadline: Date = DEFAULT_DEADLINE, + val priority: TaskPriority = TaskPriority.LOW, + val completed: Boolean = false +)Copy the code

You can through our the Kotlin Vocabulary | Kotlin default parameters to know more information about the default parameters.

Object keyword and singleton

The singleton pattern is probably one of the most common design patterns used by software developers. It allows us to create a single instance of an object that other objects can access and share.

When creating a singleton, you need to control how the object is created to ensure that only one instance exists and that your code is thread-safe. In Kotlin, you use only one keyword: object.

/* Copyright 2020 Google LLC. SPDX-License-Identifier: Apache-2.0 */ -public class Singleton{-private static volatile Singleton INSTANCE; - private Singleton(){} - public static Singleton getInstance(){ - if (INSTANCE == null) { // Single Checked - synchronized (Singleton.class) { - if (INSTANCE == null) { // Double checked - INSTANCE = new Singleton(); - } - } - } - return INSTANCE; - } - private int count = 0; - public int count(){ return count++; } - } + object Singleton { + private var count = 0 + fun count(): Int { + return count++ + } + }Copy the code

Operators, string templates, and more

The simplicity and simplicity of Kotlin is also reflected in operator overloading, deconstruction, and string templates. These features make the code very readable.

For example, suppose we have a library and some books. The operation to remove a book from a library and process and print its title could be written as follows:

/* Copyright 2020 Google LLC.spdx-license-Identifier: Apache-2.0 */

fun borrow(a){
    library -= book
    val (title, author) = book
    println("Borrowed $title")}Copy the code

The Kotlin functions used here are:

  • - =The implementation of theOperator overloading;
  • val (title, author) = bookUsing thedeconstruction;
  • println ("Borrowed $title")String templates are used.

conclusion

Kotlin makes it easy to read and write code, with built-in implementations of patterns such as singletons and delegates to help remove code that might cause bugs or increase maintenance costs. Features like string templates, lambda expressions, extension functions, and operator overloading can make code more concise. Writing less code means less code to read, which also means less code to maintain and fewer bugs, leading to higher productivity.

You can read about building Better Apps with Kotlin to learn more, and read about learning use cases to see how developers are benefiting from Kotlin. If you want to take your first steps in using Kotlin, one of the world’s most popular languages, check out our Getting Started page.