kotlin-stdlib/kotlin.random/Random/Default

Default

object Default : Random, Serializable(source)

The default random number generator.

On JVM this generator is thread-safe, its methods can be invoked from multiple threads.

Since Kotlin

1.3

Samples

import kotlin.math.sin
import kotlin.random.Random
import kotlin.test.assertTrue

fun main() { 
   //sampleStart 
   val randomValues = List(10) { Random.nextInt(0, 100) }
// prints new sequence every time
println(randomValues)

val nextValues = List(10) { Random.nextInt(0, 100) }
println(nextValues)
println("randomValues != nextValues is ${randomValues != nextValues}") // true 
   //sampleEnd
}

Functions

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fun Random.asJavaRandom(): Random

Creates a java.util.Random instance that uses the specified Kotlin Random generator as a randomness source.

Since Kotlin 1.3
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open override fun nextBits(bitCount: Int): Int

Gets the next random bitCount number of bits.

Since Kotlin 1.3
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open override fun nextBoolean(): Boolean

Gets the next random Boolean value.

Since Kotlin 1.3
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open override fun nextBytes(array: ByteArray): ByteArray

Fills the specified byte array with random bytes and returns it.

Since Kotlin 1.3
open override fun nextBytes(size: Int): ByteArray

Creates a byte array of the specified size, filled with random bytes.

Since Kotlin 1.3
open override fun nextBytes(array: ByteArray, fromIndex: Int, toIndex: Int): ByteArray

Fills a subrange of the specified byte array starting from fromIndex inclusive and ending toIndex exclusive with random bytes.

Since Kotlin 1.3
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open override fun nextDouble(): Double

Gets the next random Double value uniformly distributed between 0 (inclusive) and 1 (exclusive).

Since Kotlin 1.3
open override fun nextDouble(until: Double): Double

Gets the next random non-negative Double from the random number generator less than the specified until bound.

Since Kotlin 1.3
open override fun nextDouble(from: Double, until: Double): Double

Gets the next random Double from the random number generator in the specified range.

Since Kotlin 1.3
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open override fun nextFloat(): Float

Gets the next random Float value uniformly distributed between 0 (inclusive) and 1 (exclusive).

Since Kotlin 1.3
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open override fun nextInt(): Int

Gets the next random Int from the random number generator.

Since Kotlin 1.3
open override fun nextInt(until: Int): Int

Gets the next random non-negative Int from the random number generator less than the specified until bound.

Since Kotlin 1.3
open override fun nextInt(from: Int, until: Int): Int

Gets the next random Int from the random number generator in the specified range.

Since Kotlin 1.3
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fun Random.nextInt(range: IntRange): Int

Gets the next random Int from the random number generator in the specified range.

Since Kotlin 1.3
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open override fun nextLong(): Long

Gets the next random Long from the random number generator.

Since Kotlin 1.3
open override fun nextLong(until: Long): Long

Gets the next random non-negative Long from the random number generator less than the specified until bound.

Since Kotlin 1.3
open override fun nextLong(from: Long, until: Long): Long

Gets the next random Long from the random number generator in the specified range.

Since Kotlin 1.3
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fun Random.nextLong(range: LongRange): Long

Gets the next random Long from the random number generator in the specified range.

Since Kotlin 1.3
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@ExperimentalUnsignedTypes
fun Random.nextUBytes(size: Int): UByteArray

Creates an unsigned byte array of the specified size, filled with random bytes.

Since Kotlin 1.3
@ExperimentalUnsignedTypes
fun Random.nextUBytes(array: UByteArray): UByteArray

Fills the specified unsigned byte array with random bytes and returns it.

Since Kotlin 1.3
@ExperimentalUnsignedTypes
fun Random.nextUBytes(array: UByteArray, fromIndex: Int = 0, toIndex: Int = array.size): UByteArray

Fills a subrange of the specified UByte array starting from fromIndex inclusive and ending toIndex exclusive with random UBytes.

Since Kotlin 1.3