blocks|key|4349648|text|首先，您需要一个RNG。在Kotlin中，您目前需要使用特定于平台的Kotlin+(没有内置的Kotlin)。对于JVM，它是java.util.Random。您需要创建它的一个实例，然后调用random.nextInt(n)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4349649|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/util/Random.html^0|1R|G|2O|H|1R|G|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@$9|S|A|T|1|U]]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

First, you need a RNG. In Kotlin you currently need to use the platform specific ones (there isn't a Kotlin built in one). For the JVM it's <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Random.html" rel="nofollow noreferrer"><code>java.util.Random</code></a>. You'll need to create an instance of it and then call <code>random.nextInt(n)</code>.

blocks|key|4349990|text|生成一个介于from(包含)和to(不包含)之间的随机整数|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4349991|import+java.util.Random

val+random+=+Random()

fun+rand(from:+Int,+to:+Int)+:+Int+{
++++return+random.nextInt(to+-+from)+%2B+from
}|code-block|syntax|javascript|4349992|entityMap^0|6|4|F|2|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Generate a random integer between <code>from</code>(inclusive) and <code>to</code>(exclusive)

<pre><code>import java.util.Random

val random = Random()

fun rand(from: Int, to: Int) : Int {
 return random.nextInt(to - from) + from
}
</code></pre>

blocks|key|4349698|text|没有执行此操作的标准方法，但您可以使用Math.random()或java.util.Random类轻松创建自己的方法。下面是一个使用Math.random()方法的示例：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4349699|fun+random(n:+Int)+=+(Math.random()+*+n).toInt()
fun+random(from:+Int,+to:+Int)+=+(Math.random()+*+(to+-+from)+%2B+from).toInt()
fun+random(pair:+Pair<Int,+Int>)+=+random(pair.first,+pair.second)

fun+main(args:+Array<String>)+{
++++val+n+=+10

++++val+rand1+=+random(n)
++++val+rand2+=+random(5,+n)
++++val+rand3+=+random(5+to+n)

++++println(List(10)+{+random(n)+})
++++println(List(10)+{+random(5+to+n)+})
}|code-block|syntax|javascript|4349700|这是一个示例输出：|4349701|[9,+8,+1,+7,+5,+6,+9,+8,+1,+9]
[5,+8,+9,+7,+6,+6,+8,+6,+7,+9]|4349702|entityMap^0|J|D|X|G|1V|D|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|P|$]]

There is no standard method that does this but you can easily create your own using either <code>Math.random()</code> or the class <code>java.util.Random</code>. Here is an example using the <code>Math.random()</code> method:

<pre><code>fun random(n: Int) = (Math.random() * n).toInt()
fun random(from: Int, to: Int) = (Math.random() * (to - from) + from).toInt()
fun random(pair: Pair&lt;Int, Int&gt;) = random(pair.first, pair.second)

fun main(args: Array&lt;String&gt;) {
 val n = 10

 val rand1 = random(n)
 val rand2 = random(5, n)
 val rand3 = random(5 to n)

 println(List(10) { random(n) })
 println(List(10) { random(5 to n) })
}
</code></pre>

This is a sample output:

<pre><code>[9, 8, 1, 7, 5, 6, 9, 8, 1, 9]
[5, 8, 9, 7, 6, 6, 8, 6, 7, 9]
</code></pre>

blocks|key|4350059|text|您可以创建一个类似于java.util.Random.nextInt(int)的extension+function，但是它的绑定使用IntRange而不是Int：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4350060|fun+Random.nextInt(range:+IntRange):+Int+{
++++return+range.start+%2B+nextInt(range.last+-+range.start)
}|code-block|syntax|javascript|4350061|现在，您可以将其用于任何Random实例：|4350062|val+random+=+Random()
println(random.nextInt(5..9))+//+prints+5,+6,+7,+8,+or+9|4350063|如果您不想管理自己的Random实例，那么您可以使用例如ThreadLocalRandom.current()来定义一个方便的方法|4350064|fun+rand(range:+IntRange):+Int+{
++++return+ThreadLocalRandom.current().nextInt(range)
}|4350065|现在您可以像在Ruby中那样获取一个随机整数，而不必首先自己声明一个Random实例：|4350066|rand(5..9)+//+returns+5,+6,+7,+8,+or+9|4350067|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/util/Random.html#nextInt-int-|1|https://kotlinlang.org/docs/reference/extensions.html#extension-functions|2|https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/-int-range/|3|https://docs.oracle.com/javase/8/docs/api/java/util/Random.html|4|https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ThreadLocalRandom.html#current--^0|A|T|1V|8|26|3|A|T|0|14|I|1|1V|8|2|0|0|C|6|C|6|3|0|0|A|6|S|R|S|R|4|0|0|Y|6|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]|$9|1M|A|1N|1|1O]|$9|1P|A|1Q|1|1R]]|E|$]]|$1|F|3|G|5|H|7|1S|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1T|8|@$9|1U|A|1V|B|C]]|D|@$9|1W|A|1X|1|1Y]]|E|$]]|$1|M|3|N|5|H|7|1Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|20|8|@$9|21|A|22|B|C]|$9|23|A|24|B|C]]|D|@$9|25|A|26|1|27]]|E|$]]|$1|Q|3|R|5|H|7|28|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|29|8|@$9|2A|A|2B|B|C]]|D|@]|E|$]]|$1|U|3|V|5|H|7|2C|8|@]|D|@]|E|$I|J]]|$1|W|3|-4|5|6|7|2D|8|@]|D|@]|E|$]]]|X|$Y|$5|Z|10|11|E|$12|13]]|14|$5|Z|10|11|E|$12|15]]|16|$5|Z|10|11|E|$12|17]]|18|$5|Z|10|11|E|$12|19]]|1A|$5|Z|10|11|E|$12|1B]]]]

You can create an <a href="https://kotlinlang.org/docs/reference/extensions.html#extension-functions" rel="nofollow noreferrer">extension function</a> similar to <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Random.html#nextInt-int-" rel="nofollow noreferrer"><code>java.util.Random.nextInt(int)</code></a> but one that takes an <a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/-int-range/" rel="nofollow noreferrer"><code>IntRange</code></a> instead of an <code>Int</code> for its bound:
<pre><code>fun Random.nextInt(range: IntRange): Int {
 return range.start + nextInt(range.last - range.start)
}
</code></pre>
You can now use this with any <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Random.html" rel="nofollow noreferrer"><code>Random</code></a> instance:
<pre><code>val random = Random()
println(random.nextInt(5..9)) // prints 5, 6, 7, 8, or 9
</code></pre>
If you don't want to have to manage your own <code>Random</code> instance then you can define a convenience method using, for example, <a href="https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ThreadLocalRandom.html#current--" rel="nofollow noreferrer"><code>ThreadLocalRandom.current()</code></a>:
<pre><code>fun rand(range: IntRange): Int {
 return ThreadLocalRandom.current().nextInt(range)
}
</code></pre>
Now you can get a random integer as you would in Ruby without having to first declare a <code>Random</code> instance yourself:
<pre><code>rand(5..9) // returns 5, 6, 7, 8, or 9
</code></pre>

blocks|key|4349778|text|使用顶级函数，您可以实现与Ruby中完全相同的调用语法(如您所愿)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4349779|fun+rand(s:+Int,+e:+Int)+=+Random.nextInt(s,+e+%2B+1)|code-block|syntax|javascript|4349780|用法：|4349781|rand(1,+3)+//+returns+either+1,+2+or+3|4349782|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Using a top-level function, you can achieve exactly the same call syntax as in Ruby (as you wish):

<pre><code>fun rand(s: Int, e: Int) = Random.nextInt(s, e + 1)
</code></pre>

Usage:

<pre><code>rand(1, 3) // returns either 1, 2 or 3
</code></pre>

blocks|key|4349802|text|如果要选择的数字不是连续的，则可以使用random()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4349803|用法：|4349804|val+list+=+listOf(3,+1,+4,+5)
val+number+=+list.random()|code-block|syntax|javascript|4349805|返回列表中的一个数字。|4349806|entityMap|0|LINK|mutability|MUTABLE|url|https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/random.html^0|J|8|J|8|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|6|7|12|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|14|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

If the numbers you want to choose from are not consecutive, you can use <a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/random.html" rel="nofollow noreferrer"><code>random()</code></a>.

Usage:

<pre><code>val list = listOf(3, 1, 4, 5)
val number = list.random()
</code></pre>

Returns one of the numbers which are in the list.

blocks|key|4350172|text|从kotlin+1.2开始，你可以这样写：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350173|(1..3).shuffled().last()|offset|length|style|CODE|4350174|只要注意它是大的O(n)，但是对于一个很小的列表(特别是唯一值的列表)，它是可以的:D|4350175|entityMap^0|0|0|O|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

As of kotlin 1.2, you could write: 

<code>(1..3).shuffled().last()</code>

Just be aware it's big O(n), but for a small list (especially of unique values) it's alright :D

blocks|key|4350234|text|Kotlin+>=+1.3，多平台随机支持|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350235|在1.3版本中，标准库为随机数提供了多平台支持，请参阅this+answer。|offset|length|4350236|JavaScript上的Kotlin+<+1.3|4350237|如果您使用的是Kotlin+JavaScript，但没有访问java.util.Random的权限，则可以执行以下操作：|style|CODE|4350238|fun+IntRange.random()+=+(Math.random()+*+((endInclusive+%2B+1)+-+start)+%2B+start).toInt()|code-block|syntax|javascript|4350239|如下所示：|4350240|//+will+return+an+`Int`+between+0+and+10+(incl.)
(0..10).random()|4350241|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/45687695/8073652^0|0|R|4|0|0|0|U|G|0|0|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|13|8|@]|9|@$D|14|E|15|1|16]]|A|$]]|$1|F|3|G|5|6|7|17|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|18|8|@$D|19|E|1A|J|K]]|9|@]|A|$]]|$1|L|3|M|5|N|7|1B|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|1C|8|@]|9|@]|A|$]]|$1|S|3|T|5|N|7|1D|8|@]|9|@]|A|$O|P]]|$1|U|3|-4|5|6|7|1E|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]]]

<h2>Kotlin >= 1.3, multiplatform support for Random</h2>

As of 1.3, the standard library provided multi-platform support for randoms, see <a href="https://stackoverflow.com/a/45687695/8073652">this</a> answer.

<h2>Kotlin &lt; 1.3 on JavaScript</h2>

If you are working with Kotlin JavaScript and don't have access to <code>java.util.Random</code>, the following will work:

<pre><code>fun IntRange.random() = (Math.random() * ((endInclusive + 1) - start) + start).toInt()
</code></pre>

Used like this:

<pre><code>// will return an `Int` between 0 and 10 (incl.)
(0..10).random()
</code></pre>

blocks|key|4349918|text|1，10范围内的随机示例|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4349919|val+random1+=+(0..10).shuffled().last()|code-block|syntax|javascript|4349920|或者利用Java+Random|4349921|val+random2+=+Random().nextInt(10)+%2B+1|4349922|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Examples random in the range [1, 10] 

<pre><code>val random1 = (0..10).shuffled().last()
</code></pre>

or utilizing Java Random

<pre><code>val random2 = Random().nextInt(10) + 1
</code></pre>

blocks|key|4350296|text|实现s1m0nw1答案的另一种方法是通过变量访问它。这并不是说它的效率更高，但它使您不必键入()。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350297|val+ClosedRange<Int>.random:+Int
++++get()+=+Random().nextInt((endInclusive+%2B+1)+-+start)+%2B++start+|code-block|syntax|javascript|4350298|现在可以像这样访问它了|4350299|(1..10).random|4350300|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Another way of implementing s1m0nw1's answer would be to access it through a variable. Not that its any more efficient but it saves you from having to type ().

<pre><code>val ClosedRange&lt;Int&gt;.random: Int
 get() = Random().nextInt((endInclusive + 1) - start) + start 
</code></pre>

And now it can be accessed as such

<pre><code>(1..10).random
</code></pre>

blocks|key|4350333|text|在Kotlin+SDK+>=1.3中，你可以这样做|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350334|import+kotlin.random.Random

val+number+=+Random.nextInt(limit)|code-block|syntax|javascript|4350335|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In Kotlin SDK &gt;=1.3 you can do it like
<pre><code>import kotlin.random.Random

val number = Random.nextInt(limit)
</code></pre>

blocks|key|4350018|text|成为超级duper+))|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350019|+fun+rnd_int(min:+Int,+max:+Int):+Int+{
++++++++var+max+=+max
++++++++max+-=+min
++++++++return+(Math.random()+*+%2B%2Bmax).toInt()+%2B+min
++++}|code-block|syntax|javascript|4350020|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

to be super duper ))

<pre><code> fun rnd_int(min: Int, max: Int): Int {
 var max = max
 max -= min
 return (Math.random() * ++max).toInt() + min
 }
</code></pre>

blocks|key|4350041|text|不再需要使用自定义扩展函数。IntRange现在有一个开箱即用的random()扩展功能。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4350042|val+randomNumber+=+(0..10).random()|code-block|syntax|javascript|4350043|entityMap|0|LINK|mutability|MUTABLE|url|https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/-int-range/index.html|1|https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/random.html#random^0|W|8|E|8|0|W|8|1|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]|$9|10|A|11|1|12]]|E|$]]|$1|F|3|G|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]|S|$5|N|O|P|E|$Q|T]]]]

No need to use custom extension functions anymore. <a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/-int-range/index.html" rel="nofollow noreferrer">IntRange</a> has a <a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.ranges/random.html#random" rel="nofollow noreferrer"><code>random()</code></a> extension function out-of-the-box now.

<pre><code>val randomNumber = (0..10).random()
</code></pre>

blocks|key|4350420|text|完整的源代码。可以控制是否允许重复。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350421|import+kotlin.math.min

abstract+class+Random+{

++++companion+object+{
++++++++fun+string(length:+Int,+isUnique:+Boolean+=+false):+String+{
++++++++++++if+(0+==+length)+return+""
++++++++++++val+alphabet:+List<Char>+=+('a'..'z')+%2B+('A'..'Z')+%2B+('0'..'9')+//+Add+your+set+here.

++++++++++++if+(isUnique)+{
++++++++++++++++val+limit+=+min(length,+alphabet.count())
++++++++++++++++val+set+=+mutableSetOf<Char>()
++++++++++++++++do+{+set.add(alphabet.random())+}+while+(set.count()+!=+limit)
++++++++++++++++return+set.joinToString("")
++++++++++++}
++++++++++++return+List(length)+{+alphabet.random()+}.joinToString("")
++++++++}

++++++++fun+alphabet(length:+Int,+isUnique:+Boolean+=+false):+String+{
++++++++++++if+(0+==+length)+return+""
++++++++++++val+alphabet+=+('A'..'Z')
++++++++++++if+(isUnique)+{
++++++++++++++++val+limit+=+min(length,+alphabet.count())
++++++++++++++++val+set+=+mutableSetOf<Char>()
++++++++++++++++do+{+set.add(alphabet.random())+}+while+(set.count()+!=+limit)
++++++++++++++++return+set.joinToString("")
++++++++++++}

++++++++++++return+List(length)+{+alphabet.random()+}.joinToString("")
++++++++}
++++}
}|code-block|syntax|javascript|4350422|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Full source code. Can control whether duplicates are allowed.

<pre><code>import kotlin.math.min

abstract class Random {

 companion object {
 fun string(length: Int, isUnique: Boolean = false): String {
 if (0 == length) return ""
 val alphabet: List&lt;Char&gt; = ('a'..'z') + ('A'..'Z') + ('0'..'9') // Add your set here.

 if (isUnique) {
 val limit = min(length, alphabet.count())
 val set = mutableSetOf&lt;Char&gt;()
 do { set.add(alphabet.random()) } while (set.count() != limit)
 return set.joinToString("")
 }
 return List(length) { alphabet.random() }.joinToString("")
 }

 fun alphabet(length: Int, isUnique: Boolean = false): String {
 if (0 == length) return ""
 val alphabet = ('A'..'Z')
 if (isUnique) {
 val limit = min(length, alphabet.count())
 val set = mutableSetOf&lt;Char&gt;()
 do { set.add(alphabet.random()) } while (set.count() != limit)
 return set.joinToString("")
 }

 return List(length) { alphabet.random() }.joinToString("")
 }
 }
}
</code></pre>

blocks|key|4350120|text|当你想根据用户需求生成key或mac地址的十六进制数字，并且也使用android和kotlin时，那么你可以使用下面的代码来帮助你：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350121|private+fun+getRandomHexString(random:+SecureRandom,+numOfCharsToBePresentInTheHexString:+Int):+String+{
++++val+sb+=+StringBuilder()
++++while+(sb.length+<+numOfCharsToBePresentInTheHexString)+{
++++++++val+randomNumber+=+random.nextInt()
++++++++val+number+=+String.format("%2508X",+randomNumber)
++++++++sb.append(number)
++++}
++++return+sb.toString()
}+|code-block|syntax|javascript|4350122|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Whenever there is a situation where you want to generate key or mac address which is hexadecimal number having digits based on user demand, and that too using android and kotlin, then you my below code helps you:
<pre><code>private fun getRandomHexString(random: SecureRandom, numOfCharsToBePresentInTheHexString: Int): String {
 val sb = StringBuilder()
 while (sb.length &lt; numOfCharsToBePresentInTheHexString) {
 val randomNumber = random.nextInt()
 val number = String.format(&quot;%08X&quot;, randomNumber)
 sb.append(number)
 }
 return sb.toString()
} 
</code></pre>

blocks|key|4350169|text|下面的Kotlin对我来说效果很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4350170|(fromNumber.rangeTo(toNumber)).random()|code-block|syntax|javascript|4350171|数字范围以变量fromNumber开始，以变量toNumber结束。fromNumber和toNumber也将包含在由此生成的随机数中。|offset|length|style|CODE|4350172|entityMap^0|0|0|7|A|N|8|Y|A|19|8|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]|$I|V|J|W|K|L]|$I|X|J|Y|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|N|$]]

Below in Kotlin worked well for me:
<pre><code>(fromNumber.rangeTo(toNumber)).random()
</code></pre>
Range of the numbers starts with variable <code>fromNumber</code> and ends with variable <code>toNumber</code>. <code>fromNumber</code> and <code>toNumber</code> will also be included in the random numbers generated out of this.

A generic method that can return a random integer between 2 parameters like ruby does with <code>rand(0..n)</code>.

Any suggestion?

How can I get a random number in Kotlin?

一个泛型方法，可以返回两个参数之间的随机整数，就像ruby对rand(0..n)所做的那样。有什么建议吗？

问我如何在Kotlin中获得一个随机数？
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