Kotlin® Notes for Professionals book

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Chapter 1: Getting started with Kotlin
Section 1.1: Hello World
Section 1.2: Hello World using a Companion Object
Section 1.3: Hello World using an Object Declaration
Section 1.4: Main methods using varargs
Section 1.5: Compile and Run Kotlin Code in Command Line
Section 1.6: Reading input from Command Line
Chapter 2: Basics of Kotlin
Section 2.1: Basic examples
Chapter 3: Strings
Section 3.1: String Equality
Section 3.2: String Literals
Section 3.3: Elements of String
Section 3.4: String Templates
Chapter 4: Arrays
Section 4.1: Generic Arrays
Section 4.2: Arrays of Primitives
Section 4.3: Create an array
Section 4.4: Create an array using a closure
Section 4.5: Create an uninitialized array
Section 4.6: Extensions
Section 4.7: Iterate Array
Chapter 5: Collections
Section 5.1: Using list
Section 5.2: Using map
Section 5.3: Using set
Chapter 6: Enum
Section 6.1: Initialization
Section 6.2: Functions and Properties in enums
Section 6.3: Simple enum
Section 6.4: Mutability
Chapter 7: Functions
Section 7.1: Function References
Section 7.2: Basic Functions
Section 7.3: Inline Functions
Section 7.4: Lambda Functions
Section 7.5: Operator functions
Section 7.6: Functions Taking Other Functions
Section 7.7: Shorthand Functions
Chapter 8: Vararg Parameters in Functions
Section 8.1: Basics: Using the vararg keyword
Section 8.2: Spread Operator: Passing arrays into vararg functions
Chapter 9: Conditional Statements
Section 9.1: When-statement argument matching
Section 9.2: When-statement as expression
Section 9.3: Standard if-statement
Section 9.4: If-statement as an expression
Section 9.5: When-statement instead of if-else-if chains
Section 9.6: When-statement with enums
Chapter 10: Loops in Kotlin
Section 10.1: Looping over iterables
Section 10.2: Repeat an action x times
Section 10.3: Break and continue
Section 10.4: Iterating over a Map in kotlin
Section 10.5: Recursion
Section 10.6: While Loops
Section 10.7: Functional constructs for iteration
Chapter 11: Ranges
Section 11.1: Integral Type Ranges
Section 11.2: downTo() function
Section 11.3: step() function
Section 11.4: until function
Chapter 12: Regex
Section 12.1: Idioms for Regex Matching in When Expression
Section 12.2: Introduction to regular expressions in Kotlin
Chapter 13: Basic Lambdas
Section 13.1: Lambda as parameter to filter function
Section 13.2: Lambda for benchmarking a function call
Section 13.3: Lambda passed as a variable
Chapter 14: Null Safety
Section 14.1: Smart casts
Section 14.2: Assertion
Section 14.3: Eliminate nulls from an Iterable and array
Section 14.4: Null Coalescing / Elvis Operator
Section 14.5: Nullable and Non-Nullable types
Section 14.6: Elvis Operator (?:)
Section 14.7: Safe call operator
Chapter 15: Class Delegation
Section 15.1: Delegate a method to another class
Chapter 16: Class Inheritance
Section 16.1: Basics: the 'open' keyword
Section 16.2: Inheriting fields from a class
Section 16.3: Inheriting methods from a class
Section 16.4: Overriding properties and methods
Chapter 17: Visibility Modifiers
Section 17.1: Code Sample
Chapter 18: Generics
Section 18.1: Declaration-site variance
Section 18.2: Use-site variance
Chapter 19: Interfaces
Section 19.1: Interface with default implementations
Section 19.2: Properties in Interfaces
Section 19.3: super keyword
Section 19.4: Basic Interface
Section 19.5: Conflicts when Implementing Multiple Interfaces with Default Implementations
Chapter 20: Singleton objects
Section 20.1: Use as replacement of static methods/fields of java
Section 20.2: Use as a singleton
Chapter 21: coroutines
Section 21.1: Simple coroutine which delay's 1 second but not blocks
Chapter 22: Annotations
Section 22.1: Meta-annotations
Section 22.2: Declaring an annotation
Chapter 23: Type aliases
Section 23.1: Function type
Section 23.2: Generic type
Chapter 24: Type-Safe Builders
Section 24.1: Type-safe tree structure builder
Chapter 25: Delegated properties
Section 25.1: Observable properties
Section 25.2: Custom delegation
Section 25.3: Lazy initialization
Section 25.4: Map-backed properties
Section 25.5: Delegate Can be used as a layer to reduce boilerplate
Chapter 26: Reflection
Section 26.1: Referencing a class
Section 26.2: Inter-operating with Java reflection
Section 26.3: Referencing a function
Section 26.4: Getting values of all properties of a class
Section 26.5: Setting values of all properties of a class
Chapter 27: Extension Methods
Section 27.1: Potential Pitfall: Extensions are Resolved Statically
Section 27.2: Top-Level Extensions
Section 27.3: Lazy extension property workaround
Section 27.4: Sample extending Java 7+ Path class
Section 27.5: Sample extending long to render a human readable string
Section 27.6: Sample extending Java 8 Temporal classes to render an ISO formatted string
Section 27.7: Using extension functions to improve readability
Section 27.8: Extension functions to Companion Objects (appearance of Static functions)
Section 27.9: Extensions for easier reference View from code
Chapter 28: DSL Building
Section 28.1: Infix approach to build DSL
Section 28.2: Using operators with lambdas
Section 28.3: Overriding invoke method to build DSL
Section 28.4: Using extensions with lambdas
Chapter 29: Idioms
Section 29.1: Serializable and serialVersionUid in Kotlin
Section 29.2: Delegate to a class without providing it in the public constructor
Section 29.3: Use let or also to simplify working with nullable objects
Section 29.4: Use apply to initialize objects or to achieve method chaining
Section 29.5: Fluent methods in Kotlin
Section 29.6: Filtering a list
Section 29.7: Creating DTOs (POJOs/POCOs)
Chapter 30: RecyclerView in Kotlin
Section 30.1: Main class and Adapter
Chapter 31: logging in kotlin
Section 31.1: kotlin.logging
Chapter 32: Exceptions
Section 32.1: Catching exception with try-catch-finally
Chapter 33: JUnit
Section 33.1: Rules
Chapter 34: Kotlin Android Extensions
Section 34.1: Using Views
Section 34.2: Configuration
Section 34.3: Painful listener for getting notice, when the view is completely drawn now is so simple and awesome with Kotlin's extension
Section 34.4: Product flavors
Chapter 35: Kotlin for Java Developers
Section 35.1: Declaring Variables
Section 35.2: Quick Facts
Section 35.3: Equality & Identity
Section 35.4: IF, TRY and others are expressions, not statements
Chapter 36: Java 8 Stream Equivalents
Section 36.1: Accumulate names in a List
Section 36.2: Collect example #5 - find people of legal age, output formatted string
Section 36.3: Collect example #6 - group people by age, print age and names together
Section 36.4: Dierent Kinds of Streams #7 - lazily iterate Doubles, map to Int, map to String, print each
Section 36.5: Counting items in a list after filter is applied
Section 36.6: Convert elements to strings and concatenate them, separated by commas
Section 36.7: Compute sum of salaries of employee
Section 36.8: Group employees by department
Section 36.9: Compute sum of salaries by department
Section 36.10: Partition students into passing and failing
Section 36.11: Names of male members
Section 36.12: Group names of members in roster by gender
Section 36.13: Filter a list to another list
Section 36.14: Finding shortest string a list
Section 36.15: Dierent Kinds of Streams #2 - lazily using first item if exists
Section 36.16: Dierent Kinds of Streams #3 - iterate a range of Integers
Section 36.17: Dierent Kinds of Streams #4 - iterate an array, map the values, calculate the average
Section 36.18: Dierent Kinds of Streams #5 - lazily iterate a list of strings, map the values, convert to Int, find max
Section 36.19: Dierent Kinds of Streams #6 - lazily iterate a stream of Ints, map the values, print results
Section 36.20: How streams work - filter, upper case, then sort a list
Section 36.21: Dierent Kinds of Streams #1 - eager using first item if it exists
Section 36.22: Collect example #7a - Map names, join together with delimiter
Section 36.23: Collect example #7b - Collect with SummarizingInt
Chapter 37: Kotlin Caveats
Section 37.1: Calling a toString() on a nullable type
Appendix A: Configuring Kotlin build
Section A.1: Gradle configuration
Section A.2: Using Android Studio
Section A.3: Migrating from Gradle using Groovy script to Kotlin script
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