Long Data type Usage and Type Conversion in Kotlin

Definition

• Long is a 64-bit number in Kotlin The type can be either declared explicitly or the compiler itself has the ability to infer the type of the assigned value.
• The long data type can have values from -(2^63) to (2^63)-1. Any value less than -(2^31) or greater than (2^31)-1 is inferred automatically by the compiler as a Long value.
• In JVM, the characteristics of this “Long” variable is derived from the characteristics of primitive type “long” of Java which has a non-nullable default value.

Syntax and declaration

A Long value can be declared by 3 ways as mentioned below.

1. Mentioning type explicitly

val variable_name : Long = value

for example,

val number : Long = 1000

2. Number type is automatically inferred

val variable_name = value

for example,
//Number type is automatically inferred
val number = 1000001234567

3. Declaring and Initializing separately

var variable_name : Long 
variable_name = value

for example

//Declaring and Initializing separately
var number:Long 
number = 10001

Long Datatype Example Program in Kotlin

// Long Datatype Kotlin example program
// Data type Kotlin Programs, Basic Kotlin Programs
	
fun main(args:Array<String>) {
    //Assigning value to Long variable explicitly
    val a:Long = 768
    //Declaring a Long value immediately
    val b:Long = 1000012345677
    
    println("Long value in a is $a")
    println("Long value in b is $b")
}

Sample Output

Long value in a is 768
Long value in b is 1000012345677

Type conversion syntax and declaration

//String to Long Conversion 
val variable_name = "string".toLong()

//Int to Long Conversion 
val variable_name = int_variable.toLong()

Long type Conversion Example Program in Kotlin

// Long Datatype Kotlin example program
// Data type Kotlin Programs, Basic Kotlin Programs

fun main(args: Array < String > ) {
    //Converted from String and Long type is inferred
    val num1 = "1006787676766".toLong()

    //Conversion from String and Declaring an Long value immediately
    val num2: Long = "309878".toLong()

    val num3: Int = 10
    //Conversion from Int
    val num4: Long = num3.toLong()

    val num5: Float = 20.31f
    //Conversion from Float
    val num6: Long = num5.toLong()

    //Print values after conversion
    println("String to Long : num1 Value : $num1")
    println("String to Long : num2 Value : $num2")
    println("Int Value : num3 Value : $num3")
    println("Int to Long : num4 Value : $num4")
    println("Float Value : num5 Value : $num5")
    println("Float to Long : num6 Value : $num6")
}

Sample Output

String to Long : num1 Value : 50
String to Long : num2 Value : 30
Int Value : num3 Value : 10
Int to Long : num4 Value : 10
Float Value : num5 Value : 20.31
Float to Long : num6 Value : 20

How It Works

This Kotlin program demonstrates Long Data type Usage and Type Conversion. It first prepares the data it needs, then performs the core operation step by step, and finally prints the output shown in the Sample Output above.

1. Declare the variables that hold the program’s data.
2. Print the final result to the console so you can compare it with the sample output.

Try changing the input values and re-running the program to see how the output changes — this is the fastest way to understand how the logic behaves.