Java 不同数据类型内容比较，是否相同

    public static void main(String[] args) {

        System.out.println(Objects.equals(null, null));//true
        System.out.println(Objects.equals(null, ""));//false
        System.out.println(Objects.equals("", ""));//true
        System.out.println(Objects.equals(1, 1));//true
        System.out.println(Objects.equals(1, 2));//false

        System.out.println(Objects.equals("a", "b"));//false
        System.out.println(Objects.equals("a1", "a1"));//true


        String[] str1 = {"a","b","c"};
        String[] str2 = {"a1","b","c"};
        System.out.println(Arrays.equals(str1, str2));//false

        String[] str3 = null;
        System.out.println(Arrays.equals(str1, str3));//false

        System.out.println(Arrays.equals(str3, str3));//true

        String[] str4 = new String[3];
        System.out.println(Arrays.equals(str1, str4));//false
        System.out.println(Arrays.equals(str4, str4));//true

        String[] str5 = {"a","b","c"};
        System.out.println(Arrays.equals(str1, str5));//true


        List<Integer> list1 = new ArrayList<>();
        List<Integer> list2 = new ArrayList<>();
        System.out.println(list1.equals(list2));//true
        list1.add(1);
        list2.add(1);
        System.out.println(list1.equals(list2));//true
        list2.add(2);
        System.out.println(list1.equals(list2));//false
        list1 = null;
        System.out.println(list2.equals(list1));//false
        System.out.println(list1.equals(list1));//error
        System.out.println(list1.equals(list2));//error
        

        List<Integer> list11 = new ArrayList<>();
        List<Integer> list22 = new ArrayList<>();
        System.out.println(list11.containsAll(list22));//true
        list11.add(1);
        list22 .add(1);
        System.out.println(list11.containsAll(list22));//true
        list22 .add(2);
        System.out.println(list11.containsAll(list22));//false
        list11= null;
        System.out.println(list22 .containsAll(list11));//error
        System.out.println(list11.containsAll(list11));//error
        System.out.println(list11.containsAll(list22));//error


    }
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