Java 数组去重

1、利用HashMap实现数组去重

String arra[]= {"1","12","1","13","15","23","15"};Map<String,Object> map =new HashMap<String,Object>();  for(int i=0;i<arra.length;i++){  map.put(arra[i], arra[i]);  }  List<Object> list = new ArrayList<Object>();  for(String in:map.keySet()){  Object str= map.get(in);  list.add(str);System.out.println(in + "    "+str);  }System.out.println(list.toString());//[1, 12, 23, 13, 15]  Object[] object = list.toArray();  System.out.println(object.length);

2、利用ArrayList的contains实现数组去重

String arra[]= {"1","12","1","13","15","23","15"};List<String> list = new ArrayList<String>();for(String item:arra){if(!list.contains(item)){//存入不重复的项list.add(item);}}System.out.println(list.toString());//[1, 12, 13, 15, 23]