Variables and Data Types

Kotlin has two types of variables: val and var.

val: Immutable variable. Once assigned, cannot be reassigned.

var: Mutable variable. Can be reassigned.

val name: String = "Kotlin" // name = "C#" (This is an error, can't be reassigned)

var age: Int = 10 // age = 12 (This is allowed)

// var or val init variable with out assigning the data is error

val userName: String // it's an error since there is no data assigned

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Data Types

Kotlin is statically typed, meaning the type of a variable is known at compile time.

Integers

Byte, Short, Int, Long

Unsigned integers

UByte, UShort, UInt, ULong

Floating-point numbers

Float, Double

Booleans

Boolean

Characters

Char

Strings

String

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Examples:

val integer: Int = 10

val longNumber: Long = 100L

val doubleNumber: Double = 10.5

val floatNumber: Float = 10.5F

val booleanValue: Boolean = true

val charValue: Char = 'A'

val stringValue: String = "Hello"

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