数组

1.判断数组内是否有反复元素

/**判断String数组内是否有反复元素*/    public static boolean checkRepeat(String[] strings){        boolean result = false;        List<String> list = new ArrayList<>();        for (int i=0; i < strings.length; i++){            if (!list.contains(strings[i])){                list.add(strings[i]);            }        }        if (list.size() < strings.length){            result = true;            return result;        }else {            return result;        }    }

测试：

后果：

2.数组转为List汇合

（1）Collections.addAll()办法

System.out.println("----------数组转为List汇合：Collections.addAll()办法-----------------------------------");        String[] strings = {"aa","bb","cc"};        List<String> list3 = new ArrayList<>();        Collections.addAll(list3, strings);        System.out.println(list3.toString());

测试：

（2）循环增加数组元素的办法

System.out.println("----------数组转为List汇合：循环增加数组元素的办法-----------------------------------");        String[] string4 = {"aa","bb","cc","dd"};        List<String> list4 = new ArrayList<>();        for (int i=0; i<string4.length; i++){            list4.add(string4[i]);        }        System.out.println(list4.toString());

测试：

（3）Arrays.asList()办法
返回一个受指定数组反对的固定大小的列表，不能做Add、Remove等操作

System.out.println("----------数组转为List汇合：Arrays.asList()办法-----------------------------------");        String[] string5 = {"aa","bb","cc","dd","ee"};        List<String> list5 = new ArrayList<>();        list5 = Arrays.asList(string5);        System.out.println(list5.toString());

测试：