Kotlin countLeadingZeroBits()

Kotlin countLeadingZeroBits()

In Kotlin, the countLeadingZeroBits() function is used to count the number of leading zero bits in the binary representation of a number.

This function can be helpful in various bitwise operations and optimizations where knowledge of the number of leading zeros is required.

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

Syntax

The syntax of the countLeadingZeroBits() function is:

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

The function returns the count of leading zero bits in the binary representation of this value.

Example

1. Basic usage of countLeadingZeroBits()

In this example, we’ll use countLeadingZeroBits() to count the number of leading zero bits for the number 18.

Kotlin Program

fun main() {
    val number = 18
    val result = number.countLeadingZeroBits()
    println("Number of leading zero bits for $number is $result")
}

Output

Number of leading zero bits for 18 is 27

2. Using countLeadingZeroBits() for Optimization

In this example, we’ll use countLeadingZeroBits() to optimize the search for the highest bit set in an integer.

Kotlin Program

fun findHighestBitSet(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 highest bit set using countLeadingZeroBits
    return 31 - value.countLeadingZeroBits()
}

fun main() {
    val number = 18
    val highestBitPosition = findHighestBitSet(number)
    
    println("The highest bit set in $number is at position $highestBitPosition")
}

Output

The highest bit set in 18 is at position 4

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

Summary

In this tutorial, we’ve covered the countLeadingZeroBits() function in Kotlin, its syntax, and how to use it for counting leading zero bits in the binary representation of an integer. This function can be particularly useful in bitwise operations and optimizations where knowledge of the number of leading zeros is essential.