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.