An introduction to Scala.js
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The document provides an overview of Scala.js, a technology combining Scala's object-oriented and functional programming benefits with high-performance JavaScript optimization. It highlights Scala.js's advantages such as strong typing for code correctness, performance enhancements, compatibility with JavaScript libraries, and excellent editor support. Additionally, it includes code comparisons between JavaScript, TypeScript, and Scala.js, along with community resources for support.
![JS & Scala.js
const personMap = new Map([
[10, new Person("Roger", "Moore")],
[20, new Person("James", "Bond")]]);
const names = [];
for (const [key, person] of personMap)
{
if (key > 15)
{
names.push(`${key} = ${person.firstName}`);
}
}
val personMap = Map(
10 -> new Person("Roger", "Moore"),
20 -> new Person("James", "Bond"))
val names = for
{
(key, person) <- personMap
if key > 15
} yield s"$key = ${person.firstName}"](https://image.slidesharecdn.com/scala-js-webinar-210414065446/85/An-introduction-to-Scala-js-10-320.jpg)
![TypeScript & Scala.js
const personMap = new Map<number, Person>([
[10, new Person("Roger", "Moore")],
[20, new Person("James", "Bond")]]);
const names = new Array<string>();
for (const [key, person] of personMap)
{
if (key > 15)
{
names.push(`${key} = ${person.firstName}`);
}
}
val personMap = Map(
10 -> new Person("Roger", "Moore"),
20 -> new Person("James", "Bond"))
val names = for
{
(key, person) <- personMap
if key > 15
} yield s"$key = ${person.firstName}"](https://image.slidesharecdn.com/scala-js-webinar-210414065446/85/An-introduction-to-Scala-js-15-320.jpg)
![Community Support
● https://stackoverflow.com/users/1829647/sjrd -> @sjrd author of scala-js and very much active to
answer the query related to Scala-js.
● https://stackoverflow.com/ -> Stack Overflow has good community support for scala-js with tag as
[scala.js].
● https://gitter.im/scala-js/scala-js -> Gitter channel for scala-js for quick and fast response.](https://image.slidesharecdn.com/scala-js-webinar-210414065446/85/An-introduction-to-Scala-js-19-320.jpg)
An introduction to Scala.js
- 1. An introduction to scala-js Presented By: Divyanshu Srivastava Software Consultant Knoldus Inc.
- 2. About Knoldus Knoldus is a technology consulting firm with focus on modernizing the digital systems at the pace your business demands. DevOps Functional. Reactive. Cloud Native
- 3. Our Agenda ● Introduction to Scala.js ● Code Comparison: JS & Scala.js ● Code Comparison: TypeScript & Scala.js ● Chart based comparison : JS, TypeScript & Scala.js ● Demo ● Community Support ● References
- 4. Introduction
- 5. The Scala Programming Language Scala combines object-oriented and functional programming in one concise, high-level language. Scala's static types help avoid bugs in complex applications, and its JVM and JavaScript runtimes let you build high-performance systems with easy access to huge ecosystems of libraries. - scala-lang.org
- 6. Why Scala.js? ● Correctness :- Strong typing guarantees our code to be free from silly mistakes. ● Performance :- Scala.js optimizes our Scala code into highly efficient JavaScript. ● Interoperability:- We can use any JavaScript library right from our Scala.js code, either in a statically or dynamically typed way, including most popular one React and AngularJs ● Excellent editor support: - With Scala.js, typos and type-errors are immediately caught and shown on our editor, without even needing to compile our code, refactor any field or method with ease.
- 7. Code Comparison: JS & Scala.js
- 8. JS & Scala.js class Person { constructor(firstName, lastName) { this.firstName = firstName; this.lastName = lastName; } fullName() { return `${this.firstName} ${this.lastName}`; } } class Person(val firstName: String, val lastName: String) { def fullName(): String = s"$firstName $lastName" }
- 9. JS & Scala.js console.log("Hello World!"); println("Hello World!") const names = persons .map(p =>p.firstName); val names = persons .map(p => p.firstName) val names = persons.map(_.firstName)
- 10. JS & Scala.js const personMap = new Map([ [10, new Person("Roger", "Moore")], [20, new Person("James", "Bond")]]); const names = []; for (const [key, person] of personMap) { if (key > 15) { names.push(`${key} = ${person.firstName}`); } } val personMap = Map( 10 -> new Person("Roger", "Moore"), 20 -> new Person("James", "Bond")) val names = for { (key, person) <- personMap if key > 15 } yield s"$key = ${person.firstName}"
- 11. JS & Scala.js const xhr = new XMLHttpRequest(); xhr.open("GET", "http://localhost:8080”); xhr.onload = (e) => { if (xhr.status === 200) { const r = JSON.parse(xhr.responseText); $("#id").html(parse(r)); } }; xhr.send(); val xhr = new XMLHttpRequest() xhr.open("GET", "http://localhost:8080”) xhr.onload = { (e: Event) => if (xhr.status == 200) { val r = JSON.parse(xhr.responseText) $("#id").html(parse(r)) } } xhr.send()
- 12. Code Comparison: TypeScript & Scala.js
- 13. TypeScript & Scala.js class Person { public firstName: String; public lastName: String; constructor(firstName: string, lastName: string) { this.firstName = firstName; this.lastName = lastName; } fullName() { return `${this.firstName} ${this.lastName}`; } } class Person(val firstName: String, val lastName: String) { def fullName(): String = s"$firstName $lastName" }
- 14. TypeScript & Scala.js console.log("Hello World!"); println("Hello World!") const names = persons .map(p =>p.firstName); val names = persons .map(p => p.firstName) val names = persons.map(_.firstName)
- 15. TypeScript & Scala.js const personMap = new Map<number, Person>([ [10, new Person("Roger", "Moore")], [20, new Person("James", "Bond")]]); const names = new Array<string>(); for (const [key, person] of personMap) { if (key > 15) { names.push(`${key} = ${person.firstName}`); } } val personMap = Map( 10 -> new Person("Roger", "Moore"), 20 -> new Person("James", "Bond")) val names = for { (key, person) <- personMap if key > 15 } yield s"$key = ${person.firstName}"
- 16. Chart based comparison : JS, TypeScript & Scala.js
- 18. DEMO
- 19. Community Support ● https://stackoverflow.com/users/1829647/sjrd -> @sjrd author of scala-js and very much active to answer the query related to Scala-js. ● https://stackoverflow.com/ -> Stack Overflow has good community support for scala-js with tag as [scala.js]. ● https://gitter.im/scala-js/scala-js -> Gitter channel for scala-js for quick and fast response.
- 20. ● https://www.scala-js.org/ ● https://www.scala-js.org/doc/sjs-for-js/ ● https://www.lihaoyi.com/hands-on-scala-js/#GettingStarted ● https://www.scala-lang.org/ References