从 json 字符串中提取数据返回错误

Question

我在 php 文件中有这段代码

[
{
    "_id": "549f065925e1928098c74275",
    "index": 0,
    "guid": "c21b3720-430e-4be3-9309-e8afbabc0020",
    "email": "browningriley@zilodyne.com",
    "phone": "+1 (804) 417-2615",
    "address": "657 Temple Court, Katonah, Mississippi, 7139",
    "about": "Ut laborum ut nostrud dolore ut aute irure aliquip duis. Amet proident fugiat cupidatat nulla ullamco adipisicing ea excepteur. Proident in ullamco aute reprehenderit ea. Consequat non cupidatat id sit nostrud non. Velit amet exercitation incididunt aliqua deserunt cupidatat et ex.\r\n",
    "registered": "2014-09-05T01:48:12 -03:00",
    "latitude": -44.882099,
    "longitude": 24.574332,
    "tags": [
        "officia",
        "consectetur",
        "incididunt",
        "eu",
        "magna",
        "esse",
        "elit"
    ],
    "friends": [
        {
            "id": 0,
            "name": "Billie Jarvis"
        },
        {
            "id": 1,
            "name": "Laurie Espinoza"
        },
        {
            "id": 2,
            "name": "Kate Stuart"
        }
    ],
    "greeting": "Hello, Browning Riley! You have 6 unread messages.",
    "favoriteFruit": "banana"
},
{
    "_id": "549f065925aa17df2fd6ebea",
    "index": 1,
    "guid": "9cf247e8-fe6b-4c42-a4a3-24ef7b907ad4",
    "email": "bonitasharp@medalert.com",
    "phone": "+1 (946) 506-2141",
    "address": "414 Willoughby Avenue, Gila, California, 4696",
    "about": "Aliqua aute tempor veniam sit esse velit anim. Proident amet aliqua ad non labore eu voluptate labore in amet exercitation irure. Qui laborum ea aliqua consectetur minim aliqua amet minim laborum sint fugiat ullamco nulla elit.\r\n",
    "registered": "2014-02-11T20:29:39 -02:00",
    "latitude": -19.03677,
    "longitude": 138.137275,
    "tags": [
        "eu",
        "non",
        "et",
        "nostrud",
        "enim",
        "proident",
        "sint"
    ],
    "friends": [
        {
            "id": 0,
            "name": "Gamble Porter"
        },
        {
            "id": 1,
            "name": "Jami Bell"
        },
        {
            "id": 2,
            "name": "Mullen Alexander"
        }
    ],
    "greeting": "Hello, Bonita Sharp! You have 5 unread messages.",
    "favoriteFruit": "strawberry"
}
]

现在尝试从这个字符串中提取数据，如下所示

 $("#get").on('click',function(){

            $.get('data.php',function(data){
                console.log(data);
                var json_array = data;
                var new_array = [];
                $.each(json_array,function(i,o) {
                 new_array.push(o._id);
                });

                console.log(new_array);

        });
    });

但这是结果“TypeError: invalid 'in' operand a”，您可以在此处看到in this online example。 php文件是data.php，代码在script.js文件中

Answer 1

您只需将dataType 设置为'json' 或使用自动设置数据类型的$.getJSON()。

这将告诉$.ajax 会发生什么并相应地解析它

     $.get('data.php',function(data){

                var myarray = data;
                console.log(myarray);
                var new_array = [];
                $.each(myarray,function(i,o) {
                 new_array.push(o._id);
                });

                console.log(new_array);


            $("#result").text(new_array);
        },'json');/* last argument is "dataType" */

文件的内容标头未作为application/json发送

DEMO

Answer 2

您需要解析您的 php 响应：
data = JSON.parse(data)
请参阅此plunker（第 7 行已更新）

原因是你在响应中得到一个字符串，然后你需要将它解析为JSON，你按照上面的例子来做。