# Kotlin countTrailingZeroBits()

## Kotlin countTrailingZeroBits()

In Kotlin, the `countTrailingZeroBits()` function is used to count the number of trailing zero bits in the binary representation of an integer.

This function is particularly useful in bit manipulation and optimization scenarios where knowledge of the number of trailing zeros is essential.

In this tutorial, we’ll explore the syntax of the `countTrailingZeroBits()` function and provide examples of its usage in Kotlin.

## Syntax

The syntax of the `countTrailingZeroBits()` function is:

``````fun Byte.countTrailingZeroBits(): Int
fun Short.countTrailingZeroBits(): Int
fun UInt.countTrailingZeroBits(): Int
fun ULong.countTrailingZeroBits(): Int
fun UByte.countTrailingZeroBits(): Int
fun UShort.countTrailingZeroBits(): Int
fun Int.countTrailingZeroBits(): Int
fun Long.countTrailingZeroBits(): Int``````

The `countOneBits()` function is an extension function for the specified numeric classes, and returns the count of trailing zero bits in the binary representation of the integer.

## Examples

### 1. Basic usage of countTrailingZeroBits()

In this example, we’ll use `countTrailingZeroBits()` to count the trailing zero bits for given integer `1024`.

Kotlin Program

``````fun main() {
val number = 1024
val result = number.countTrailingZeroBits()
println("Number of trailing zero bits in \$number is \$result")
}``````

Output

``Number of trailing zero bits in 1024 is 10``

### 2. Using countTrailingZeroBits() for Bitwise Optimization

In this example, we’ll use `countTrailingZeroBits()` to optimize a bitwise operation by finding the position of the rightmost set bit.

Kotlin Program

``````fun findRightmostSetBitPosition(value: Int): Int {
// If the value is 0, return -1 indicating no bit is set
if (value == 0) return -1

// Calculate the position of the rightmost set bit using countTrailingZeroBits
return value.countTrailingZeroBits()
}

fun main() {
val number = 1024
val rightmostSetBitPosition = findRightmostSetBitPosition(number)

println("The rightmost set bit in \$number is at position \$rightmostSetBitPosition")
}``````

Output

``The rightmost set bit in 1024 is at position 10``

In this example, the `countTrailingZeroBits()` function is used to find the position of the rightmost set bit in the binary representation of the given integer. The result is then printed.

## Summary

In this tutorial, we’ve covered the `countTrailingZeroBits()` function in Kotlin, its syntax, and how to use it for counting trailing zero bits in the binary representation of an integer. This function can be valuable in scenarios where you need to optimize bitwise operations or determine the position of the rightmost set bit in an integer.