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Kotlin Dictionary

Kotlin Dictionary Index

[Setup] Kotlin Development Environment	Setup instructions for installing and running Kotlin.
val / var	Declares immutable and mutable variables.
Basic Data Types	Types for numbers, characters, and booleans.
String Templates	A syntax for embedding variables and expressions inside strings.
String.length / String.isEmpty()	Gets the length of a string and checks if it is empty.
String.substring() / drop() / take()	Extracts a substring.
String.replace() / trim()	Replaces parts of a string and trims whitespace.
String.split() / joinToString()	Splits and joins strings.
String.toInt() / toDouble()	Converts a string to a numeric value.
if Expressions	Conditional branching as an expression with a return value.
when Expressions	A syntax for multi-branch and type-checking conditions.
Ranges and for Loops	Range operators and loops.
Defining Functions with fun	Declares a function with parameters and a return type.
Single-Expression Functions / Local Functions	Concise function definitions.
Lambda Expressions	Defines and passes anonymous functions.
Higher-Order Functions	A mechanism that uses functions as arguments or return values.
Inline Functions	Inline expansion of lambda expressions.
Nullable Types / ?. Operator	The basics of safely handling null values.
?: Elvis Operator	An operator that specifies a default value when the expression is null.
!! Non-Null Assertion	An operator that forcibly converts a nullable to a non-null type.
Scope-Limited Processing with let	A way to safely process a value after a null check.
Smart Casts / as?	Automatic casting after a type check.
class / Constructor	Class definition and primary constructor.
data class	A class specialized for holding data.
sealed class / sealed interface	A restricted inheritance hierarchy.
enum class	Defines and uses enumeration types.
object / companion object	Singletons and static members.
open / override	Inheritance and method overriding.
interface	Defines and implements interfaces.
Extension Functions	A mechanism to add methods to existing classes.
Custom Getters / Setters	Defining property accessors.
lateinit / lazy	A mechanism for deferred initialization.
Delegated Properties	A mechanism to delegate a property to another object.
Destructuring Declarations	Assigning multiple variables simultaneously.
let	A scope function used for null checks and transformation chains.
run / with	A scope function used for object setup.
apply	A scope function used for object configuration and initialization.
also	A scope function used for debugging and side-effect insertion.
List — Creating / listOf() / mutableListOf()	Creating a list and basic access.
List — filter() / map()	Filtering and transforming elements.
List — find() / first() / any() / all()	Searching elements and checking conditions.
List — sortedBy() / sortedWith()	Sorting a list.
List — flatMap() / flatten()	Flattening nested lists.
List — reduce() / fold()	Folding elements into a single value.
List — groupBy() / partition()	Grouping and partitioning elements.
List — zip() / unzip()	Combining two lists together.
List — forEach() / forEachIndexed()	Iterating over elements.
Map — mapOf() / mutableMapOf()	Creating and manipulating a map.
Set — setOf() / mutableSetOf()	Creating a set and performing set operations.
sequenceOf() / generateSequence()	Creating a lazily evaluated sequence.
Sequences — Terminal Operations	Retrieving results from a sequence.
Generics — Basics	Defining and using type parameters.
Covariance / Contravariance	Variance annotations for generics.
Reified Type Parameters	A mechanism to retain type information at runtime.
Type Aliases / typealias	Syntax for giving a type an alias.
try / catch / finally	Basic syntax for exception handling.
require() / check() / error()	Checking preconditions and state.
Operator Overloading	Redefining operators.
@JvmStatic / @JvmField	Annotations for Java interoperability.
Suspend Functions	Defining suspendable functions.
launch / async	Launching coroutines.
await() / Deferred	Retrieving asynchronous results.
delay() / withTimeout()	Waiting and setting timeouts.
Flow — Basics	Asynchronous data streams.
Channel	Data communication between coroutines.

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