Convert a floating-point value to nearest int in Kotlin

This article explores different ways to convert a floating-point value to the nearest integer in Kotlin.

For example, when x = 10.55f, the output should be 11 and for x = -10.55f, the output should be -11.

1. Using `roundToInt()` function

The standard solution is to use the roundToInt() function to round the floating-point value to the nearest integer. This function additionally convert a floating-point value x to Int.MAX_VALUE when x > Int.MAX_VALUE and to Int.MIN_VALUE when x < Int.MIN_VALUE.

import kotlin.math.roundToInt

fun main() {

val x = 10.55f

val y: Int = x.roundToInt()

println("y = $y") // y = 11

}

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2. Using `toInt()` function

Typecasting in Kotlin simply truncates the floating-point value and does not round it to the nearest integer, as shown below:

fun main() {

val x = 10.55f

val y: Int = x.toInt()

println("y = $y") // y = 10

}

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There’s a workaround for this.

To round the given floating-point positive value x, you can use the expression (x + 0.5).toInt(). Similarly, to round a floating-point negative value x, you can use the expression (x - 0.5).toInt(). This is demonstrated below:

fun main() {

val x = 10.55f

val y: Int

if (x > 0) {

y = (x + 0.5).toInt()

}

else {

y = (x - 0.5).toInt()

}

println("y = $y") // y = 11

}

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That’s all about converting a floating-point value to the nearest integer in Kotlin.

Convert a floating-point value to nearest int in Kotlin

1. Using roundToInt() function

2. Using toInt() function

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1. Using `roundToInt()` function

2. Using `toInt()` function