Java Collections shuffle()
shuffle()是一种Java Collections 类方法，它通过随机排列指定的列表元素来工作。有
两种不同类型的Java shuffle()方法，可以根据其参数进行区分。这些是:
Java Collections shuffle(List
list)方法
Java Collections shuffle(List
list, Random random)方法
Java Collections shuffle(list)方法
shuffle(list)方法用于通过使用
default 随机性。
Java Collections shuffle(List
list, Random random)方法
shuffle(List
list, Random random)方法用于对列表进行随机重新排序元素使用
指定的随机性。
语法
以下是
shuffle()方法的声明:
public static void shuffle(List<?> list)
public static void shuffle(List<?> list, Random random)
参数
| 参数 |
说明 |
必需/可选 |
| list |
这是将被改组的列表。 |
必需 |
| random |
它是随机源，用于随机排列列表。 |
必需 |
返回
shuffle()方法不返回任何内容。
异常
UnsupportedOperationException -如果指定的列表或其列表迭代器不支持set操作，则此方法引发异常。
兼容性版本
Java 1.5及更高版本
示例1
import java.util.*;
public class CollectionsShuffleExample1 {
public static void main(String[] args) {
List<String> list = Arrays.asList("A", "B", "C", "D");
System.out.println("List before Shuffle : "+list);
Collections.shuffle(list);
System.out.println("List after shuffle : "+list);
}
}
输出:
List before Shuffle : [A, B, C, D]
List after shuffle : [A, C, D, B]
示例2
import java.util.*;
public class CollectionsShuffleExample2 {
public static void main(String[] args) {
//Create linked list object
LinkedList<Integer> list = new LinkedList<Integer>();
//Add values in the list
list.add(10);
list.add(-20);
list.add(50);
list.add(90);
list.add(-15);
System.out.println("List before Shuffle : "+list);
Collections.shuffle(list);
System.out.println("List after shuffle : "+list);
}
}
输出:
List before Shuffle : [10, -20, 50, 90, -15]
List after shuffle : [10, 50, 90, -15, -20]
示例3
import java.util.*;
public class CollectionsShuffleExample3 {
public static void main(String[] args) {
//Create linked list object
LinkedList<Integer> list = new LinkedList<Integer>();
//Add values in the list
list.add(45);
list.add(20);
list.add(55);
list.add(90);
list.add(15);
System.out.println("List before Shuffle = "+list);
//We use Random() to shuffle given list.
Collections.shuffle(list, new Random());
System.out.println("Shuffled List with Random() = "+list);
//We use Random(3) to shuffle given list.
Collections.shuffle(list, new Random(3));
System.out.println("Shuffled List with Random(3) = "+list);
}
}
输出:
List before Shuffle = [45, 20, 55, 90, 15]
Shuffled List with Random() = [45, 55, 15, 90, 20]
Shuffled List with Random(3) = [90, 55, 45, 15, 20]
示例4
import java.util.*;
public class CollectionsShuffleExample4 {
public static void main(String[] args) {
List<String> list = Arrays.asList("one", "two", "three", "four");
System.out.println(list);
Collections.shuffle(list, new Random(2));
System.out.println(list);
}
}
输出:
[one, two, three, four]
[four, two, one, three]
