Language Basics

Lessons

1. 01 Kotlin's Place Introduces Kotlin's place on the JVM and its design goals; measures how the same `==` operator gives equality under four different criteria across eight values. 15 min read
2. 02 Variables Introduces declaration with `val` and `var`, type inference, and the `const val` constant; measures that the same string constant is a single object in two variables. 15 min read
3. 03 Basic Types Introduces the number types, the character, and the logical value; measures that the criterion of equality changes once a nullable `Int` is boxed. 15 min read
4. 04 String Templates Introduces string templates, raw strings, and the `trimIndent` function; measures that a string built with a template falls under the content criterion, while a single-variable template stays a singleton. 15 min read
5. 05 Control Flow Introduces the `if` and `when` expressions, the `is` check, and the `for` loop; measures that a `when` branch matches with `==` and does not hit for an ordinary class instance. 14 min read
6. 06 Functions Introduces parameters with default values, named arguments, and the `vararg` parameter; measures that a function reference gives a separate but equal object each time it is taken. 15 min read
7. 07 Lambdas and Higher-Order Functions Introduces lambda syntax, function types, and functions that take functions; measures that two lambda expressions are not equal, while a lambda that captures nothing is a single object. 13 min read
8. 08 Scope Functions Introduces the scope functions `let`, `run`, `with`, `apply`, and `also`; measures whether the receiver is `this` or `it` and what each returns, and shows that the result does not change the equality criterion. 14 min read