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

Value store in a variable is of some data type, it specifies how much space it occupies in memory location. As the kotlin is statically typed language so, 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 size limit.

Example of Number

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. 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 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
    }
}