javascript - 检查 JSON 对象中是否不存在值

Question

我想通过过滤字符串数组来检查给定对象中是否不存在某个值。

我想检查 keys 数组中的值是否包含在我正在循环的 JSON 对象中。如果其中一个值不存在，我必须执行其他操作，但前提是不存在的值(在 resArray 中)包含在 keys 数组中。

JSON here

这是我尝试过的:

var keys = [
    "total_kills",
    "total_deaths",
    "total_planted_bombs",
    "total_defused_bombs",
    "total_kills_knife",
    "total_kills_headshot",
    "total_wins_pistolround",
    "total_wins_map_de_dust2",
    "last_match_wins",
    "total_shots_fired",
    "total_shots_hit",
    "total_rounds_played",
    "total_kills_taser",
    "last_match_kills",
    "last_match_deaths",
    "total_kills_hegrenade",
  ];

  var resArray = stats.playerstats.stats;
  var statsArray = [];

  for (var i = 0; i < keys.length; i++) {
    for(var j = 0; j < resArray.length; j++){

        //if the value in keys array exists, do something
        if(resArray[j]["name"] === keys[i]){
         //do something
       }
       if(<value doesn't exist)>)
         //do something else.
    }
  }

已解决:

function contains(obj, key, value) {
        return obj.hasOwnProperty(key) && obj[key] === value;
      } 

      var resArray = stats.playerstats.stats;
      var statsArray = [];

      for (var i = 0; i < keys.length; i++) {

        resArray.some(function(found){

          if(contains(found, "name", keys[i])){

            statsArray.push(found);

          }

        });

        if(typeof statsArray[i] == 'undefined'){

          console.log("Not present in array: " + keys[i]);
          statsArray.push({"name": keys[i], "value": 'None'});

        }
      }

感谢大家对此主题的回复。

Answer 1

您的示例暗示您正在根据所提供的键的统计信息和条件存在创建一个新数组。构建此数组的一个简单方法是使用 Array.prototype.map枚举您的统计数组。接下来，在每次迭代的回调中，您可以将 name 属性作为参数传递给 keys.indexOf检查您的 keys 数组中是否存在该特定的name。

var statsArray = stats.map(function(stat) {
  if (keys.indexOf(stat.name) > -1) {
    return stat;
  } else {
    return stat.name + ' not found.';
  }
});

这将产生一个新数组，其中包含 stat 对象或不包含它的键中的缺失。但是，您可以返回任何您想要的内容，只要它是有效的数组项即可。

这是一个包含一小部分数据集的工作示例(但适用于您的原始数据集):

var keys = [
  "total_kills",
  "total_deaths",
  "total_planted_bombs",
  "total_defused_bombs",
  "total_kills_knife",
  "total_kills_headshot",
  "total_wins_pistolround",
  "total_wins_map_de_dust2",
  "last_match_wins",
  "total_shots_fired",
  "total_shots_hit",
  "total_rounds_played",
  "total_kills_taser",
  "last_match_kills",
  "last_match_deaths",
  "total_kills_hegrenade",
];

var stats = [{
  "name": "total_kills",
  "value": 25305
}, {
  "name": "total_deaths",
  "value": 27474
}, {
  "name": "total_time_played",
  "value": 1822419
}, {
  "name": "total_planted_bombs",
  "value": 1397
}, {
  "name": "total_defused_bombs",
  "value": 239
}, {
  "name": "total_wins",
  "value": 11477
}, {
  "name": "total_damage_done",
  "value": 3783962
}, {
  "name": "total_money_earned",
  "value": 65159500
}, {
  "name": "total_rescued_hostages",
  "value": 1
}, {
  "name": "total_kills_knife",
  "value": 278
}, {
  "name": "total_kills_hegrenade",
  "value": 168
}, {
  "name": "total_kills_glock",
  "value": 699
}, {
  "name": "total_kills_deagle",
  "value": 1289
}, {
  "name": "total_kills_elite",
  "value": 37
}, {
  "name": "total_kills_fiveseven",
  "value": 165
}, {
  "name": "total_kills_xm1014",
  "value": 78
}, {
  "name": "total_kills_mac10",
  "value": 154
}, {
  "name": "total_kills_ump45",
  "value": 330
}, {
  "name": "total_kills_p90",
  "value": 1105
}, {
  "name": "total_kills_awp",
  "value": 6934
}, {
  "name": "total_kills_ak47",
  "value": 4528
}, {
  "name": "total_kills_aug",
  "value": 137
}, {
  "name": "total_kills_famas",
  "value": 540
}, {
  "name": "total_kills_g3sg1",
  "value": 116
}, {
  "name": "total_kills_m249",
  "value": 50
}, {
  "name": "total_kills_headshot",
  "value": 7112
}, {
  "name": "total_kills_enemy_weapon",
  "value": 2308
}, {
  "name": "total_wins_pistolround",
  "value": 843
}, {
  "name": "total_wins_map_cs_assault",
  "value": 9
}, {
  "name": "total_wins_map_cs_italy",
  "value": 15
}, {
  "name": "total_wins_map_cs_office",
  "value": 11
}, {
  "name": "total_wins_map_de_aztec",
  "value": 71
}, {
  "name": "total_wins_map_de_cbble",
  "value": 373
}, {
  "name": "total_wins_map_de_dust2",
  "value": 4857
}, {
  "name": "total_wins_map_de_dust",
  "value": 25
}, {
  "name": "total_wins_map_de_inferno",
  "value": 777
}, {
  "name": "total_wins_map_de_nuke",
  "value": 247
}, {
  "name": "total_wins_map_de_train",
  "value": 47
}, {
  "name": "total_weapons_donated",
  "value": 2466
}, {
  "name": "total_broken_windows",
  "value": 30
}, {
  "name": "total_kills_enemy_blinded",
  "value": 566
}, {
  "name": "total_kills_knife_fight",
  "value": 67
}, {
  "name": "total_kills_against_zoomed_sniper",
  "value": 2284
}, {
  "name": "total_dominations",
  "value": 270
}, {
  "name": "total_domination_overkills",
  "value": 225
}, {
  "name": "total_revenges",
  "value": 207
}, {
  "name": "total_shots_hit",
  "value": 83704
}, {
  "name": "total_shots_fired",
  "value": 399207
}, {
  "name": "total_rounds_played",
  "value": 23419
}, {
  "name": "total_shots_deagle",
  "value": 12137
}, {
  "name": "total_shots_glock",
  "value": 21299
}, {
  "name": "total_shots_elite",
  "value": 777
}, {
  "name": "total_shots_fiveseven",
  "value": 3385
}, {
  "name": "total_shots_awp",
  "value": 22667
}];

var statsArray = stats.map(function(stat) {
  if(keys.indexOf(stat.name) > -1) {
    return stat;
  } else {
    return stat.name + ' not present in keys';
  }
});

console.log(statsArray);