JavaScript：动态添加新值以更新 JSON/对象

Question

我已经动态创建了对象（预定义），并将所有年份（2 年，2015 年和 2014 年）的所有月份（实际上 12 个月，我只展示了 3 个月）的值设置为 0。所以我的数据网格看起来所有月份都是 0 值。看下面的代码

 var arrayObj = [
               {"year" : 2015, "month" : "JAN", "value" : 0},
               {"year" : 2015, "month" : "FEB", "value" : 0},
               {"year" : 2015, "month" : "MAR", "value" : 0},
               {"year" : 2014, "month" : "JAN", "value" : 0},
               {"year" : 2014, "month" : "FEB", "value" : 0},
               {"year" : 2014, "month" : "MAR", "value" : 0}
             ];

定期，我会在表单提交后的某个时间以对象格式继续获取单月的值。

   eq. {"year" : 2015, "month" : "FEB", "value" : 2.33}

所以我的原始对象也应该相应地改变，使用 javascript 代码。像下面..

  var arrayObj = [
               {"year" : 2015, "month" : "JAN", "value" : 0},
               {"year" : 2015, "month" : "FEB", "value" : 2.33},
               {"year" : 2015, "month" : "MAR", "value" : 0},
               {"year" : 2014, "month" : "JAN", "value" : 0},
               {"year" : 2014, "month" : "FEB", "value" : 0},
               {"year" : 2014, "month" : "MAR", "value" : 0}
             ];

Answer 1

我认为在这种情况下 map 功能将是理想的。请看下面的代码段：

var src = [
           {"year" : 2015, "month" : "JAN", "value" : 0},
           {"year" : 2015, "month" : "FEB", "value" : 0},
           {"year" : 2015, "month" : "MAR", "value" : 0},
           {"year" : 2014, "month" : "JAN", "value" : 0},
           {"year" : 2014, "month" : "FEB", "value" : 0},
           {"year" : 2014, "month" : "MAR", "value" : 0}
         ];

var newRecord = {
"year": 2015,
"month": "FEB",
"value": 2.33
};

function updateJSON(src, newRecord) {
return src.map(function(item) {
  return (item.year === newRecord.year && item.month === newRecord.month) ? newRecord : item;
});
}
src = updateJSON(src, newRecord);
console.log(src);