Summary - Data types

Combine Int, Double, String and Boolean to write a calculation card.

Summary - Data types

So far you've learned integer types, floating-point types, Boolean, Char, String, Any and Unit. Each type has a purpose: Int and Long for integers, Double for floating-point, Boolean for conditions, Char for one character, String for text.

Any is the supertype of all; Unit marks functions that return no value.

Exercise Put it together

At the top level, declare val name: String = "Kotlin". Inside fun main(), print the length with println(name.length).

Show example solution

val name: String = "Kotlin"

fun main() {
    println(name.length)
}

Next step

Congratulations! You've completed the data types group. In the next group you'll build a calculator project: step by step you'll add functions and complete a working app from start to finish. You'll experience addition, subtraction, multiplication, division and error handling in a real project.

This project will bring together all the fundamentals you've learned.

Test yourself

Which is the default type for floating-point?
- Float
- Double
- Int
- Long
Show answer

Double — Double is the default floating-point type.
Match the concepts

Int

Integer
Double

Floating-point
Boolean

true/false
String

Text
Summary - Data types: fill in the missing part
```
val active: ____ = true
```
Show answer
```
val active: Boolean = true
```

Next lesson: Project design

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