How to iterate an array of objects in Javascript

Question

I have an object (obj) that contains the content of an excel sheet (using node-xlsx library). console.log(obj) gives me the following data structure:

[ { name: 'Autostar Report',
data:
 [ [Object],
   [],
   [Object],
   [Object],
   [Object],
   [Object],
   [Object],
   [Object],
   [Object],
   [Object],
   [Object],
   [],
   [object]
]}]

Each of the objects in data contain values like this:

[
            8,
            "Enugu - Abuja",
            "Sienna Executive ( 1st )",
            5,
            "9,000",
            "45,000",
            "5,500",
            "39,500"
        ],
        [
            14,
            "Enugu - Lagos",
            "Sienna Executive ( 1st )",
            5,
            "9,000",
            "45,000",
            "8,600",
            "36,400"
        ]

Each of the object contained in data contains 8 values. I want to insert the values into a database table. Each of the value goes to a field in the table. Please how do I access the values in each data object?

Be more specific. What's the name of the object? Which value(s) do you need to access? Do you need them for specific objects? Do you want a new object / array created with the value(s) you want from the object(s)? — random_user_name, Feb 06 '16 at 15:59
Possible duplicate: http://stackoverflow.com/questions/3010840/loop-through-array-in-javascript — Igor, Feb 06 '16 at 15:59
@cale_b I need to access the data property. I want to insert each row into a database. — Chibuzo, Feb 06 '16 at 16:28
You answered only one of the many questions I asked: What's the name of the object? If you need the "data" property - that contains many additional properties - what do you need from them? Show us your code for adding to the database. NOTE: To access the data property, assuming the name of the object above is "sheet", you could simply say `var data = sheet.data`. BUT, then what do you do with it? At this point, `data` is an array of objects. You'd want to get to each one, yes? — random_user_name, Feb 06 '16 at 16:36
This answer has all the bits you need: http://stackoverflow.com/a/3010848/870729 - but we can't glue it up into an answer for you without more details. Your question is unclear still. — random_user_name, Feb 06 '16 at 16:37
Possible duplicate of [Access / process (nested) objects, arrays or JSON](http://stackoverflow.com/questions/11922383/access-process-nested-objects-arrays-or-json) — Teemu, Feb 06 '16 at 17:58
@cale_b The name is obj. The objects in data doesn't contain any property, just the values that I need. Each of the value goes to a field in the database table. I don't have issue with inserting into the database. I just can't figure out how to access the values contained in the objects. — Chibuzo, Feb 06 '16 at 19:02

score 2 · Accepted Answer · answered Feb 06 '16 at 20:58

Note that you keep saying "object", when really the obj.data value is an array of arrays. With arrays, you access a value by numerical index.

So, given your data structure, and the fact that you have only selected javascript, you would access the data like so:

// ensure the object has a "data" attribute
if (obj.hasOwnProperty('data')) {
  // get the data into a variable for convenience
  var data = obj.data;
  // loop over each row
  for (i = 0; i < data.length; i++) {
    // put the row into a variable for convenience
    var row = data[i];
    // since it's an array, access each value by index
    console.log(row[0]);
    console.log(row[1]);
    console.log(row[2]);
    // ... etc ...
  }
}

Here's a working fiddle

When it comes to processing things like this, a library such as underscore or lodash sure come in handy.

Thanks so much Caleb. obj.data value is really an Array I know, it's just that [object] is shown on the console instead and I'm new to node.js. Thanks for the suggests too, I'm using underscore already, but I just couldn't apply it to this challenge cus I was still unclear about the problem I needed to solve. — Chibuzo, Feb 06 '16 at 23:15
The object obj itself was an array so I had to use obj[0].data I've inserted into the database. Thank you very much! — Chibuzo, Feb 07 '16 at 11:44

How to iterate an array of objects in Javascript

1 Answers1