收藏。Java中的nCopies（）-yiteyi-C++库

角色 收藏。士官（） 返回一个不可变列表，其中包含给定对象的n个副本。如果我们想创建一个包含给定对象n个副本的列表，这个函数会有所帮助。新分配的数据对象很小，即它包含对该数据对象的单个引用。

null

语法：

public static <T> List<T> nCopies(int number, T object)

where, number is the number of copies
of object and object represents the 
element which will appear number times
in the returned list. T represents generic type.

例外情况： 函数抛出 非法数据异常 如果价值数字小于0。

例子：

JAVA

                         // Java code to show implementation                       
                         // of Collections.nCopies()                       
                         import                                     java.util.*;                       
                                   
                         class                                     GFG {                       
                                   
                                                 // Driver code                       
                                                 public                                     static                                     void                                     main(String[] args)                       
                                                 {                       
                                   
                                                 // creating a list where first argument                       
                                                 // represents the number of copies and                       
                                                 // the second argument represents the                       
                                                 // element to be copied for 'number' times                       
                                                 // This will create 4 copies of the objects.                       
                                                 List list = Collections.nCopies(                                     4                                     ,                                     "GeeksforGeeks"                                     );                       
                                   
                                                 // Displaying the list returned                       
                                                 System.out.println(                                     "The list returned is :"                                     );                       
                                                 Iterator itr = list.iterator();                       
                                                 while                                     (itr.hasNext()) {                       
                                                 System.out.print(itr.next() +                                     " "                                     );                       
                                                 }                       
                                                 System.out.println(                                     ""                                     );                       
                                   
                                                 List list1 = Collections.nCopies(                                     3                                     ,                                     "GeeksQuiz"                                     );                       
                                   
                                                 // Displaying the list returned                       
                                                 System.out.println(                                     "The list returned is :"                                     );                       
                                                 Iterator itr1 = list1.iterator();                       
                                                 while                                     (itr1.hasNext()) {                       
                                                 System.out.print(itr1.next() +                                     " "                                     );                       
                                                 }                       
                                                 System.out.print(                                     ""                                     );                       
                                                 }                       
                         }                       

The list returned is :
GeeksforGeeks GeeksforGeeks GeeksforGeeks GeeksforGeeks 

The list returned is :
GeeksQuiz GeeksQuiz GeeksQuiz

文章版权归作者所有，未经允许请勿转载。

THE END

Java