List<Integer> cards = Lists.newArrayList(6,10,11,12,21,23,29,30,38,39,42,43,46,51,53,59,60);List<Integer> copyList = Lists.newArrayList();copyList = cards;copyList.remove(2);System.out.println("cards:"+cards);System.out.println("copyList:"+copyList); 用了等号的操作结果是
cards:[6, 10, 12, 21, 23, 29, 30, 38, 39, 42, 43, 46, 51, 53, 59, 60]
copyList:[6, 10, 12, 21, 23, 29, 30, 38, 39, 42, 43, 46, 51, 53, 59, 60]
List<Integer> cards = Lists.newArrayList(6,10,11,12,21,23,29,30,38,39,42,43,46,51,53,59,60);List<Integer> copyList = Lists.newArrayList();copyList.addAll(cards);copyList.remove(2);System.out.println("cards:"+cards);System.out.println("copyList:"+copyList); 用了add的结果
cards:[6, 10, 11, 12, 21, 23, 29, 30, 38, 39, 42, 43, 46, 51, 53, 59, 60]
copyList:[6, 10, 12, 21, 23, 29, 30, 38, 39, 42, 43, 46, 51, 53, 59, 60]
用等号操作时两个集合都会被操作,add不会
原文地址:https://www.cnblogs.com/michaelcnblogs/p/11564438.html
时间: 2024-09-30 08:11:59