Android-Kotlin Digest #2 – Basic Types

Back again with Kotlin I learnt.

Kotlin runs on Java Virtual Machine (JVM).

Syntax for declaring variables:

Mutable: var name: Type = value

Immutable: val name: Type = value

Type	Bit width
Double	64
Float	32
Long	64
Int	32
Short	16
Byte	8

Kotlin 1.1 supports underscores ( _ ) in numeric values for readability:

val mySalary = 1_000_000

val myCreditCardBill = 20_000

Difference between == and === :

val a : Int = 10

val b : Int = 10

(a == b) // gives true

(a === b) // gives true

Note: Here primitive types are compared.

When the primitive types are nullable it is turned into references and following is the result:

val a : Int? = 10

val b : Int? = 10

(a == b) // gives true

(a === b) // gives false

Note: Here a and b becomes references and hence comparision with === results false.

Type converters:

‘c’.toInt()

80.toString()

A raw string is delimited by a triple quote ( “”” ), contains no escaping and can contain newlines and any other characters:

val text = “””

for (c in “foo”)

    print(c)

“””

You can remove leading whitespace with trimMargin() function:

val text = “””

|Tell me and I forget.

|Teach me and I remember.

|Involve me and I learn.

|(Benjamin Franklin)

“””.trimMargin()

— Happy Coding —