undefined when loop objects Javascript

Question

I want to ask something which is actually I don't know what's wrong with my code. So, i've docs from database. Here is my docs :

{  
  "docs":[  
    {  
      "orderDate":{  
        "value":"2018-03-20",
        "type":"date"
      },
      "name":{  
        "value":"Abid Rakhmansyah",
        "type":"text"
      },
      "phone":{  
        "value":"082117414233",
        "type":"number"
      },
      "email":{  
        "value":"[email protected]",
        "type":"email"
      },
      "paid":{  
        "value":true,
        "type":"boolean"
      }
    },
    {  
      "orderDate":{  
        "type":"date",
        "value":"2018-03-13T05:14:00.806Z"
      },
      "name":{  
        "value":"Iqbal Maulana",
        "type":"text"
      },
      "phone":{  
        "value":"082117414233",
        "type":"number"
      },
      "email":{  
        "value":"[email protected]",
        "type":"email"
      },
      "paid":{  
        "type":"boolean",
        "value":false
      }
    },
    {  
      "orderDate":{  
        "value":"2018-03-20",
        "type":"date"
      },
      "name":{  
        "value":"Abdullah",
        "type":"text"
      },
      "phone":{  
        "value":"092034",
        "type":"number"
      },
      "email":{  
        "value":"[email protected]",
        "type":"email"
      },
      "paid":{  
        "value":true,
        "type":"boolean"
      }
    },
    {  
      "orderDate":{  
        "value":"2018-03-20",
        "type":"date"
      },
      "name":{  
        "value":"asd",
        "type":"text"
      },
      "phone":{  
        "value":"234234",
        "type":"number"
      },
      "email":{  
        "value":"[email protected]",
        "type":"email"
      },
      "paid":{  
        "value":true,
        "type":"boolean"
      }
    },
    {  
      "orderDate":{  
        "type":"date",
        "value":"2018-03-20T06:01:54.821Z"
      },
      "name":{  
        "value":"as",
        "type":"text"
      },
      "phone":{  
        "value":"082117414233",
        "type":"number"
      },
      "email":{  
        "value":"[email protected]",
        "type":"email"
      },
      "paid":{  
        "type":"boolean",
        "value":false
      }
    }
  ],
  "total":5,
  "limit":8,
  "page":1,
  "pages":1
}

I want to get only value property in the objects. So, i try to code like this.

orders.docs.forEach( function (arrayItem)
  {
    Object.keys(arrayItem.toJSON()).forEach(function(key) {
        console.log(key, JSON.stringify(arrayItem[key].value));
    });
  });

I think that it will be work. But, I don't know why... The result of my code doesn't show like what I expected. Here is the result of my code :

[0] orderDate "2018-03-20"
[0] (node:20944) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot read property 'value' of undefined

For the first loop it work fine, but when it going to 2nd loop. The value is undefined. What's is wrong?

Wouldn't toJSON turn the object to JSON. As in, a string. In that case, what are you forEach-ing on? And why would the "JSON keys" (as that's what you are forEaching, whatever that is) work on the base item? — VLAZ
– VLAZ, Commented Apr 3, 2018 at 8:21
@vlaz because when i don't use to JSON. It would return $__ undefined isNew undefined — Abid Rakhmansyah
– Abid Rakhmansyah, Commented Apr 3, 2018 at 8:26
OK, but you are still getting the keys from "JSON" and using them on the base item. Unless I'm missing something JSON is a string. Doing Object.keys on it won't actually give you the keys from the object. — VLAZ
– VLAZ, Commented Apr 3, 2018 at 8:28
Do you have the query that gives the above results? You could perform an aggregate query that uses $objectToArray operator to get the values — chridam
– chridam, Commented Apr 3, 2018 at 8:43

Xhynk · Accepted Answer · 2018-04-03 08:28:02Z

1

Are you sure you're not just overthinking it?

Here's a Demo

I'm sure it could be cleaned up further, but without modifying your code too much this can find the key and value pairs just fine:

orders = JSON.parse( orders );

orders.docs.forEach( function( arrayItem ){
    Object.keys(arrayItem).forEach( function(key) {
        console.log( key +': '+ arrayItem[key].value );
    });
});

answered Apr 3, 2018 at 8:28

Xhynk

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1 Comment

Abid Rakhmansyah Over a year ago

I am tired :( Thank you!

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