Kotlin Data Types

The most fundamental data type in Kotlin is the Primitive data type and all others are reference types like array and string. Java needs to use wrappers (java.lang.Integer) for primitive data types to behave like objects but Kotlin already has all data types as objects.

There are different data types in Kotlin:

1. Integer Data type
2. Floating-point Data Type
3. Boolean Data Type
4. Character Data Type

Integer Data Type

These data types contain integer values.

Data Type	Bits	Min Value	Max Value
byte	8 bits	-128	127
short	16 bits	-32768	32767
int	32 bits	-2147483648	2147483647
long	64 bits	-9223372036854775808	9223372036854775807

Let’s write a program to represent all the integer data types and their min and max values.

Kotlin

// Kotlin code
fun main(args : Array<String>) {
    var myint = 35

    // add suffix L for long integer
    var mylong = 23L

    println("My integer ${myint}")
    println("My long integer ${mylong}")

    var b1: Byte = Byte.MIN_VALUE
    var b2: Byte = Byte.MAX_VALUE
    println("Smallest byte value: " +b1)
    println("Largest byte value: " +b2)

    var S1: Short = Short.MIN_VALUE
    var S2: Short = Short.MAX_VALUE
    println("Smallest short value: " +S1)
    println("Largest short value: " +S2)

    var I1: Int = Int.MIN_VALUE
    var I2: Int = Int.MAX_VALUE
    println("Smallest integer value: " +I1)
    println("Largest integer value: " +I2)

    var L1: Long = Long.MIN_VALUE
    var L2: Long = Long.MAX_VALUE
    println("Smallest long integer value: " +L1)
    println("Largest long integer value: " +L2)
}

Output:

My integer 35
My long integer 23
Smallest byte value: -128
Largest byte value: 127
Smallest short value: -32768
Largest short value: 32767
Smallest integer value: -2147483648
Largest integer value: 2147483647
Smallest long integer value: -9223372036854775808
Largest long integer value: 9223372036854775807

Floating-Point Data Type

These data type used to store decimal value or fractional part.

Data Type	Bits	Min Value	Max Value
float	32 bits	1.40129846432481707e-45	3.40282346638528860e+38
double	64 bits	4.94065645841246544e-324	1.79769313486231570e+308

Let’s write a program to represent both the floating-point data type and their min and max value.

Kotlin

// Kotlin code
fun main(args : Array<String>) {
      // add suffix F for float
    var myfloat = 54F
    println("My float value ${myfloat}")

    var F1: Float = Float.MIN_VALUE
    var F2: Float = Float.MAX_VALUE
    println("Smallest Float value: " +F1)
    println("Largest Float value: " + F2)

    var D1: Double = Double.MIN_VALUE
    var D2: Double = Double.MAX_VALUE
    println("Smallest Double value: " + D1)
    println("Largest Double value: " + D2)
}

Output:

My float value 54.0
Smallest Float value: 1.4E-45
Largest Float value: 3.4028235E38
Smallest Double value: 4.9E-324
Largest Double value: 1.7976931348623157E308

Boolean Data Type

Boolean data type represents only one bit of information either true or false. The Boolean type in Kotlin is the same as in Java. These operations disjunction (||) or conjunction (&&) can be performed on boolean types.

Data Type	Bits	Data Range
boolean	1 bit	true or false

Let’s write a program to represent the boolean data types.

Kotlin

// Kotlin code
fun main(args : Array<String>){
if (true is Boolean){
        print("Yes,true is a boolean value")
    }
}

Output:

Yes, true is a boolean value

Character Data Type

Character data type represents the small letters(a-z), Capital letters(A-Z), digits(0-9) and other symbols.

Data Type	Bits	Min Value	Max Value
char	16 bits	‘\u0000’ (0)	‘\uFFFF’ (65535)

Let’s write a program to represent character data type.

Kotlin

// Kotlin code
fun main(args : Array<String>){
    var alphabet: Char = 'C'
    println("C is a character : ${alphabet is Char}")
}

Output:

C is a character : true