如何在Node.js中遍历JSON数组？

Question

我有一个 JSON 数组：

[
    {
        "art": "A",
        "count": "0",
        "name": "name1",
        "ean": "802.0079.127",
        "marker": "null",
        "stammkost": "A",
        "tablename": "IWEO_IWBB_01062015"
    },
    {
        "art": "A",
        "count": "0",
        "name": "2",
        "ean": "657.7406.559",
        "marker": "null",
        "stammkost": "A",
        "tablename": "IWEO_IWBB_02062015"
    }
]

我会使用以下代码来在PHP中循环数组以迭代表名称：

foreach($jArray as $value){ 
  $tablename = $value['tablename'];
  //some code
}

我该如何在Node.js中完成这个任务？我找到了很多相关的问题，但是没有实际的答案。其中大部分都来自2011年。

- Piet

---

JSON只是一种表示法。将其转换为本地数组，然后像往常一样执行操作，对于数组使用for(;;)，对于对象使用for..in。 - Paul S.

Answer 1

var tables = [
    { "art":"A","count":"0","name":"name1","ean":"802.0079.127","marker":"null","stammkost":"A","tablename":"IWEO_IWBB_01062015" },
    { "art":"A","count":"0","name":"2","ean":"657.7406.559","marker":"null","stammkost":"A","tablename":"IWEO_IWBB_02062015" }
];

tables.forEach(function(table) {
    var tableName = table.name;
    console.log(tableName);
});

- Clarkie

---

打印什么？我两次都得到了 '未定义' :( - Ariadne R.

Answer 2

你需要先将其反序列化为一个对象。

var arr = JSON.parse(<your json array>);
for(var i = 0; i < arr.length; i++)
{
  var tablename = arr[i].tablename;
}

- tier1

---

for..in循环用于遍历 对象 的键，您可能希望改用for循环。 - Paul S.

Answer 3

在Node中迭代数组的另一种方式：

let Arr = [
    {"art": "A","count": "0","name": "name1","ean": "802.0079.127","marker": "null","stammkost": "A","tablename": "IWEO_IWBB_01062015"},
    {"art": "A","count": "0","name": "2","ean": "657.7406.559","marker": "null","stammkost": "A","tablename": "IWEO_IWBB_02062015"}
];

for (key in Arr) {
  console.log(Arr[key]);
};

- ROOT

Answer 4

var tables = [
    { "art":"A","count":"0","name":"name1","ean":"802.0079.127","marker":"null","stammkost":"A","tablename":"IWEO_IWBB_01062015" },
    { "art":"A","count":"0","name":"2","ean":"657.7406.559","marker":"null","stammkost":"A","tablename":"IWEO_IWBB_02062015" }
];

tables.map(({name})=> console.log(name)) 

在JS中迭代使用for...in、map、forEach和reduce方法。

- Sai Jeevan Balla