Conversion of List and Set in Java

Conversion of List and Set in Java

(1) Convert List to set

 List<Long> ids=new ArrayList<>();
 HashSet<Long> set=new HashSet<>(ids);

It should be noted that when the List is converted to a Set, when there is duplicate data, the conversion will result in data loss, because the Set collection does not allow duplicate data.

(2) Set is converted to List

 HashSet<Long> set=new HashSet<>();
 List<Long> ids=new ArrayList<>(set);

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Original link: https://blog.csdn.net/qq_33036061/article/details/103968822