前后端分别判断两个数组 A数组有的元素B数据没有

前端：

            FilterData(a, b) {
                //循环判断数组a里的元素在b里面有没有，有的话就放入新建立的数组中
                //a有  b没有
                var result = new Array();
                var c = b.toString();
                for (var i = 0; i < a.length; i++) {
                    if (c.indexOf(a[i].toString()) == -1) {
                        result.push(a[i]);
                    }
                }
                return result;
            }

后端：后端通过Ip来判断数组对象元素

    private List<Map<String, String>> getOffline(List<Map<String, String>> list, List<Map<String, String>> mapList) {
        int cf = 0;
        for (int i = 0; i < mapList.size(); i++) {
            for (int j = 0; j < list.size(); j++) {
                if (mapList.get(i).get("ip").equals(list.get(j).get("ip"))) {
                    cf++;
                    break;
                }
            }
        }
        boolean flag = false;
        List<Map<String, String>> mapList2 = new ArrayList<>(mapList.size() - cf);
        int xb = 0;
        for (int i = 0; i < mapList.size(); i++) {
            for (int j = 0; j < list.size(); j++) {
                if (mapList.get(i).get("ip").equals(list.get(j).get("ip"))) {
                    flag = false;
                    break;
                } else {
                    flag = true;
                }
            }
            if (flag) {
                mapList2.add(xb, mapList.get(i));
                xb++;
            }
        }
        return mapList2;
    }