Full 2025 Kotlin Crash Course For Beginners

An introductory course in Kotlin programming, covering core syntax, null-safety, control flow, functions, collections, and object-oriented language features. Learners create a project and write a first program in IntelliJ IDEA.

Syllabus

00:00 - Introduction
1:30 - Why is Kotlin cool?
3:57 - IntelliJ Installation
5:15 - Creating the project
9:20 - Hello world program
11:32 - val and var
18:20 - Arithmetic operators
22:58 - Comparison operators
27:19 - Logical operators
32:40 - Console input
36:41 - Nullability & null-safe operators
47:27 - if conditions
55:48 - when expression
59:48 - Exceptions & try/catch
1:05:30 - Arrays
1:16:01 - Loops
1:31:10 - Normal functions
1:42:03 - Extension functions
1:49:07 - Function overloading
1:52:25 - Lambda functions
2:07:33 - Normal class & data class
2:18:28 - Interfaces
2:26:14 - Abstract classes
2:35:24 - Sealed interface & sealed class
2:37:34 - Enum classes
2:44:19 - Singletons
2:49:29 - Visibility modifiers
2:53:06 - Generics