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Yes scala can!
This document presents a promotional overview of Scala, highlighting its advantages over Java, such as functional programming features and concise syntax. It provides historical context, key differences between Scala and Java, and an introduction to Scala's features like higher-order functions, pattern matching, and traits. The presentation concludes with resources for further learning and community engagement in the Scala programming language.
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Yes scala can!
- 1. The place forsharing ideas and knowledge
- 2. Yes Scala Can! Amir Moulavi Anders Eriksson @mamirm @anders_eriksson amir.moulavi@jayway.com anders.eriksson@jayway.com Jayway Stockholm 2012-05-30
- 3. Why ● We've foundScala and like it! ● We would like to broaden the interest amongst Java developers. ● Hopefully this presentation will inspire you to look more into Scala!
- 4. Agenda ● History andBackground ● Scala vs. Java: Similarities and Differences ● Quick Journey to Scala ● Book Raffle!
- 5. It has beena revolution!
- 6. Little history andbackground ● 2001: ○ Design of Scala started ■ Goals: merge functional + object oriented paradigms ● 2004: ○ First public release on JVM
- 7. Little history andbackground ● 2006: ○ major rewrite (v 2.0) ● 2011: ○ Company Typesafe is funded for professional support
- 8. Java vs. Scala(similarities) ● Runs on JVM ● Statically typed ● Object oriented ● Garbage collected
- 9. Java vs. Scala(differences) ● Pure object orientation ● Functional paradigm ● Pattern matching ● Mixin composition
- 10. Java vs. Scala(differences) ● No checked exception ● Implicit conversions ● Flexible imports and access modifier ● Read Evaluate Print Loop (REPL) console
- 11. Scala is aunifier
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- 14. Scala is staticallytyped
- 15. Scala is concise publicclass Person { private final String name; private final int age; public Person(String name, int age) { this.name = name; this.int = int; } public String getName() { return name; Java } public int getAge() { return age; } }
- 16. Scala is concise classPerson(val name:String, val age:Int) Sc ala
- 17. Scala is expressive (1to 10) filter (_ > 7)
- 19. REPL The command linefor Scala
- 20. Tuples ( , ) ( , , ) ( , , , ) ( , , , , ) ( , , , , , )
- 21. Tuples ● Saves youthe tedium of defining simplistic data-heavy classes ● Immutable ● Each value different type ● Can contain up to 22 values ● Indexed from 1
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- 24. Case classes ● Easierinstantiation ● Immutability in constructor parameters by default ● You get these methods for free ○ toString() ○ equals() ○ hashCode() ○ apply() ○ copy()
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- 27. Pattern Matching ● Similarto Java's switch statement ● Let you match any sort of data ● First-match policy
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- 30. Higher Order Functions ●Functions are first class citizens in Scala F:A B ● Higher Order Functions are functions that take functions as input parameters or return them as results F : (A B) (R S)
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- 33. Powerful Collections ● Easyto use ○ A small vocabulary of 20-50 methods to solve most collection problems ● Concise ○ A single word instead of several loops!
- 34. Powerful Collections ● Safe ○ Functional nature + Statically typed! ● Fast ○ Tuned and optimized collections' operations ● Universal ○ The same operation on any type
- 35. Powerful Collections Scala Collections Immutable Mutable
- 36. Powerful Collections ● List ○ Immutable and ListBuffer is mutable ● Array ○ Mutable ● Set ○ Immutable and mutable ● Map ○ Immutable and mutable ● ... and String! ○
- 37. Powerful Collections withHigher Order Functions
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- 39. Traits ● Definition: ○ Provides a set of methods that implement behaviour ○ Requires a set of methods that parameterized the provided behaviour ○ Does not specify any state variables
- 40. Traits ● Interfaces withbehaviors ● Fundamental unit of code re-use ● Extremely powerful tool in OO design
- 41. Rich interfaces Traits Stackable modifications
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- 44. Parallel Collections ● Supportsthe same operations as sequential ones ● Easily convert sequential to parallel collection
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- 46. Scala and JavaIntegration ● Seamless integration ● Make full use of existing libraries and code Scala Java
- 47. Scala and JavaIntegration ● Familiar development environments ○ Eclipse, IntelliJ, Netbeans, ... ● Familiar building tools like Maven ○ SBT ● If you are a Java developer, you're halfway there!
- 48. What's Scala advantageover Java as a language choice?
- 49. ● implicit parameters ● pattern matching ● case classes ● type inferencing ● higher-kinded types ● monadic for comprehension ● variance annotation ● traits ● default and named argument ● abstract values ● by-name terms ● type aliasing ● self types ● path-dependent types ● structural types ● ...
- 50. Conclusion ● Scala isnot complex ● Express your ideas in a concise way ● Better code readability ● Scala = Functional + Object oriented paradigms. ● Scala scales with programmers
- 51. Where to gofrom here? Programming in Scala, 2nd edition by Martin Odersky, Lex Spoon and Bill Venners Scala for the Impatient by Cay Hortsmann
- 52. Where to gofrom here? Scala Stockholm User Group http://www. meetup.com/Scala-Stockholm/
- 53. Where to gofrom here? Scala course "Fast-Track to Scala" from Typesafe 18-19 September, 2012
- 54. Where to gofrom here?
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- 57. The place forsharing ideas and knowledge