如何从JSON提取属性的一个“列”

Question

我有这样的JSON数据：

{ "krs_semester": [
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "0b38a133282251406979ba675b896ec5",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000007",
     "sks": "2",
     "status": "1"
   },
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "6130bfc0ec155ff195ecc8dda6d0344c",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000005",
     "sks": "2",
     "status": "1"
   },
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "a12f7877cdd71e79660534d898ffa027",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000006",
     "sks": "2",
     "status": "1"
   }] 
}

我这样做是将所有kodesmt提取到一个数组中

var kmk = [];
var idx=0
$.each(data.krs_semester, function(key, val){
  kmk[idx] = val.kodemk;
  idx++;
})

所以，我有这个kmk数组

["13000007", "13000005", "13000006"]

有没有更简单，更有效的方法来做到这一点？

Answer 1

我将使用map()函数：

var kmk = data.krs_semester.map(function (c) {
  return c.kodemk;
});

或在ES6中：

var kmk = data.krs_semester.map(c => c.kodemk);

工作摘要

var data = { "krs_semester": [
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "0b38a133282251406979ba675b896ec5",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000007",
     "sks": "2",
     "status": "1"
   },
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "6130bfc0ec155ff195ecc8dda6d0344c",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000005",
     "sks": "2",
     "status": "1"
   },
   { "id_krs": "6723b92dd027470822d3914f8be178bd",
     "id_belanja": "a12f7877cdd71e79660534d898ffa027",
     "nimhs": "51016002",
     "kodesmt": "20182",
     "kodemk": "13000006",
     "sks": "2",
     "status": "1"
   }] 
};
var kmk = data.krs_semester.map(function (c) {
  return c.kodemk;
});
console.log(kmk);