从列表中随机选择一个项目

Question

How can I randomly select an item from a list in Java? eg I have

List<String> list = new ArrayList<String>();
list.add("One");
list.add("Two");

etc.... How can I randomly select from this list using the

Random myRandomizer = new Random();

Answer 1

Something like this?

Random randomizer = new Random();
String random = list.get(randomizer.nextInt(list.size()));

Answer 2

Clean Code:

List<String> list = new ArrayList<String>();
list.add("One");
list.add("Two");
String random = list.get(new Random().nextInt(list.size()));

Answer 3

Simple and generic solution, for retrieving random element from your collections:

public static <T> T getRandomListElement(List<T> items) {
    return items.get(ThreadLocalRandom.current().nextInt(items.size()));
}

Answer 4

If you're coding in Kotlin the simplest way is writing:

val randomElement = listName.shuffled()[0]

or

val randomElement = listName.random()

I hope it'll help you :)

Answer 5

For Kotlin, you can use

random()

defined in kotlin.collections

For example, Assuming

val results = ArrayList<Result>() //Get the list from server or add something to the list
val myRandomItem = results.random()