Kotlin Datatypes

In this article, you will learn different data types of Kotlin with examples.

5. Kotlin Datatypes 5.1 Kotlin datatypes with examples 5.2 Check data type


Kotlin DataTypes with examples

If the value store in a variable is of some data type, it specifies how much space it occupies in the memory location. As Kotlin is a statically typed language, the type of a variable is known at the compile time. There are basically five data types in Kotlin.

  • Number
  • Boolean
  • Char
  • String
  • Array

Number

These are the different number types in Kotlin with a size limit.

Type Width Description
Byte8It is used where the value of a variable within [-128, 127].
Short16It is used where the value of a variable within [-32768, 32767].
Int32It is 32 bit signed 2's complement integer.
Float32It is 32 bit single-precision floating point.
Long64It is 64 bit signed 2's complement integer.
Double64It is 64 bit double-precision floating-point.
Example of Kotlin Number DataType
fun main(args : Array<String>) {    
	val a = 22 //int
	val l = 34343L //long
	val d = 43.341 //double
	val f = 33.12F //float
	val hx = 0x64 //hexadecimal
	val b = 110010 //binary
	println("$a");
	println("$l");
	println("$d");
	println("$f");
	println("$hx");
	println("$b");
}
Output
22
34343
43.341
33.12
100
110010

In the above example, there is no need to mention the type of variables, the compiler knows that the variable a is of type int, d is of type double.



Boolean

Boolean has only two possible values, either TRUE or FALSE. Booleans are used in many condition code statements. The comparison operator always returns a boolean value.

Example of Boolean
fun main(args : Array<String>) {    
	val a = 10
	val b = 5
	val c = 8
	if(a < b && a > c)
        println("True")
    else
       println("False")
}




Character

The character data type is represented by char. It is represented by single or double quotes.

Example of Chars
fun main(args : Array<String>) {    
	val chr: Char   
	chr = 'E' 
	println("The character is $chr")
}
Output
The character is E

We can escape special characters using a backslash, like - \t, \b, \n, \r, \", \\ and \$.



String

The string is a sequence of characters enclosed within double and triple quotes. It is immutable means you cannot change the individual character of a string. It is represented by the type String.

Example of String
fun main(args : Array<String>) {    
	val str1 = "Welcome to this tutorial."
	var str2 = """This is envisioned and developed to meet basic and free courses to learn, succeed and belong."""
	println("$str1 $str2")
}

We can iterate over a string using a for loop.

fun main(args : Array<String>) {    
	val str = "Welcome to this tutorial."
	for (s in str) {
		println(s)
	}
}
Output
W
e
l
c
o
m
e
 
t
o
 
t
h
i
s
 
t
u
t
o
r
i
a
l
.

A string may contain escaped characters in them.

fun main(args : Array<String>) {    
	val s = "Hello, John!\n"
}


Array

Kotlin provides two ways to create arrays - arrayOf() and array() constructor.

Example of arrayOf()
val array1 = arrayOf(22,12,43)
Example of array() constructor
val array2 = Array(10, 'Smith', 'Jorz')


Check Kotlin data type

The is operator checks whether an object is of the given type at runtime.

fun main(args : Array<String>) {    
    var s1 = "Hello World"
    fun getStrLength(s1: Any):Int?{
        if(s1 is String) {
            return s1.length
        }
        return null
    }
}






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