Kotlin for android
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The document is a presentation about Kotlin for Android, prepared by Shady Selim for a Google I/O event. Kotlin is described as a statically typed programming language targeting the JVM that enhances development by reducing boilerplate code and supporting functional and object-oriented paradigms. It emphasizes Kotlin's strengths, such as seamless interoperability with Java and the ability to create expressive domain-specific languages without needing to rewrite existing codebases.
Kotlin for android
- 1. Kotlin for Android Prepared by Shady Selim For GDG 6 October Google I/O 17 Event On 8/7/2017
- 2. Speaker Bio • Official Google Speaker • GDG Helwan Founder & Leader • Mobile & Web Evangelist • Technology savvy • Think tank, Father • UI/UX freak • Leader & Mentor www.linkedin.com/in/shadyselim/ @dr_Shady_Selim 2
- 3. Who created Kotlin? • IntelliJ IDEA • PhpStorm • ReSharper • PyCharm • RubyMine • … others 3
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- 7. Is Kotlin Really new? 7
- 8. Why Should I care!!? • Statically typed programming language targeting the JVM • Support for functional and OO paradigms • Pragmatic, safe, concise, great Java interop • Free and open-source • Drastically reduce the amount of boilerplate code • Lambda expression • Avoid entire classes of errors such as null pointer exceptions • Java 9 is … 8
- 9. The Strengths of Kotlin • Modeling the data of your application concisely and expressively • Creating reusable abstractions using functional programming techniques • Creating expressive domain-specific languages • Java interop ensures that all existing Java frameworks can be used • No rewrite required to start using Kotlin in existing codebase • Existing investment is fully preserved 9
- 10. Java Model Example 10 public class Customer { private String name; private String email; private String company; public Customer(String name) { this(name, "", ""); } public Customer(String name, String email) { this(name, email, ""); } public Customer(String name, String email, String company) { this.name = name; this.email = email; this.company = company; }
- 11. Java Model Example, cont. 11 public String getName() { return name; } public void setName(String name) { this.name = name; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; }
- 12. Java Model Example, cont. 12 public String getCompany() { return company; } public void setCompany(String company) { this.company = company; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Customer customer = (Customer) o; if (name != null ? !name.equals(customer.name) : customer.name != null) return false; if (email != null ? !email.equals(customer.email) : customer.email != null) return false; return company != null ? company.equals(customer.company) : customer.company == null; }
- 13. Java Model Example, cont. 13 @Override public int hashCode() { int result = name != null ? name.hashCode() : 0; result = 31 * result + (email != null ? email.hashCode() : 0); result = 31 * result + (company != null ? company.hashCode() : 0); return result; } @Override public String toString() { return "Customer{" + "name='" + name + ''' + ", email='" + email + ''' + ", company='" + company + ''' + '}'; } }
- 14. Kotlin Model Example, cont. 14 data class Customer(var name: String, var email: String = "", var company: String = "")
- 15. Do you like reactive programming? 15
- 16. You will not miss your frameworks or libraries 16
- 17. You will not miss your frameworks or libraries 17
- 18. kotlin.link 18
- 19. Resources • https://kotlinlang.org/ • https://m.signalvnoise.com/kotlin-its-the-little-things-8c0f501bc6ea • https://www.jetbrains.com/ • https://www.slideshare.net/intelliyole/kotlin-why-do-you-care • https://github.com/ReactiveX/RxKotlin • https://spring.io/blog/2016/02/15/developing-spring-boot- applications-with-kotlin • https://www.slideshare.net/makingx/spring-kotlin • https://kotlin.link/ 19
- 20. Questions!? 20