If I have the following:

{"hdrs": ["Make","Model","Year"],
 "data" : [ 
   {"Make":"Honda","Model":"Accord","Year":"2008"}
   {"Make":"Toyota","Model":"Corolla","Year":"2008"}
   {"Make":"Honda","Model":"Pilot","Year":"2008"}]
}

And I have a "hdrs" name (i.e. "Make"), how can I reference the data array instances? seems like data["Make"][0] should work...but unable to get the right reference

EDIT

Sorry for the ambiguity.. I can loop through hdrs to get each hdr name, but I need to use each instance value of hdrs to find all the data elements in data (not sure that is any better of an explanation). and I will have it in a variable t since it is JSON (appreciate the re-tagging) I would like to be able to reference with something like this: t.data[hdrs[i]][j]

If I have the following:

{"hdrs": ["Make","Model","Year"],
 "data" : [ 
   {"Make":"Honda","Model":"Accord","Year":"2008"}
   {"Make":"Toyota","Model":"Corolla","Year":"2008"}
   {"Make":"Honda","Model":"Pilot","Year":"2008"}]
}

And I have a "hdrs" name (i.e. "Make"), how can I reference the data array instances? seems like data["Make"][0] should work...but unable to get the right reference

EDIT

Sorry for the ambiguity.. I can loop through hdrs to get each hdr name, but I need to use each instance value of hdrs to find all the data elements in data (not sure that is any better of an explanation). and I will have it in a variable t since it is JSON (appreciate the re-tagging) I would like to be able to reference with something like this: t.data[hdrs[i]][j]

• javascript
• json

Share Improve this question Follow edited May 14, 2013 at 13:10 Tiago Sippert 1,33277 gold badges2424 silver badges3333 bronze badges asked Sep 17, 2008 at 19:43 Jay CorbettJay Corbett 28.4k2121 gold badges5858 silver badges7474 bronze badges 2

• You're missing a ma between the array values in the data array. – Jared Commented Sep 17, 2008 at 19:50
• thanks a lot for the help..yes, I changed the names for the post and messed up the syntax, thanks again – Jay Corbett Commented Sep 17, 2008 at 20:40

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9 Answers 9

Sorted by: Reset to default 4

I had to alter your code a little:

var x = {"hdrs": ["Make","Model","Year"],
         "data" : [ 
           {"Make":"Honda","Model":"Accord","Year":"2008"},
           {"Make":"Toyota","Model":"Corolla","Year":"2008"},
           {"Make":"Honda","Model":"Pilot","Year":"2008"}]
        };

        alert( x.data[0].Make );

EDIT: in response to your edit

var x = {"hdrs": ["Make","Model","Year"],
         "data" : [ 
           {"Make":"Honda","Model":"Accord","Year":"2008"},
           {"Make":"Toyota","Model":"Corolla","Year":"2008"},
           {"Make":"Honda","Model":"Pilot","Year":"2008"}]
        };
var Header = 0; // Make
for( var i = 0; i <= x.data.length - 1; i++ )
{
    alert( x.data[i][x.hdrs[Header]] );
}           

First, you forgot your trailing mas in your data array items.

Try the following:

var obj_hash = {
    "hdrs": ["Make", "Model", "Year"],
    "data": [
        {"Make": "Honda", "Model": "Accord", "Year": "2008"},
        {"Make": "Toyota", "Model": "Corolla", "Year": "2008"},
        {"Make": "Honda", "Model": "Pilot", "Year": "2008"},
    ]
};

var ref_data = obj_hash.data;

alert(ref_data[0].Make);

@Kent Fredric: note that the last ma is not strictly needed, but allows you to more easily move lines around (i.e., if you move or add after the last line, and it didn't have a ma, you'd have to specifically remember to add one). I think it's best to always have trailing mas.

So, like this?

var theMap = /* the stuff you posted */;
var someHdr = "Make";
var whichIndex = 0;
var correspondingData = theMap["data"][whichIndex][someHdr];

That should work, if I'm understanding you correctly...

var x = {"hdrs": ["Make","Model","Year"],
 "data" : [ 
   {"Make":"Honda","Model":"Accord","Year":"2008"}
   {"Make":"Toyota","Model":"Corolla","Year":"2008"}
   {"Make":"Honda","Model":"Pilot","Year":"2008"}]
};

x.data[0].Make == "Honda"
x['data'][0]['Make']  == "Honda"

You have your array/hash lookup backwards :)

I'm not sure I understand your question, but...

Assuming the above JSON is the var obj, you want:

obj.data[0]["Make"] // == "Honda"

If you just want to refer to the field referenced by the first header, it would be something like:

obj.data[0][obj.hdrs[0]] // == "Honda"

perhaps try data[0].Make

Close, you'd use

var x = data[0].Make;
var z = data[0].Model;
var y = data[0].Year;

Your code as displayed is not syntactically correct; it needs some mas. I got this to work:

$foo = {"hdrs": ["Make","Model","Year"],
 "data" : [ 
   {"Make":"Honda","Model":"Accord","Year":"2008"},
   {"Make":"Toyota","Model":"Corolla","Year":"2008"},
   {"Make":"Honda","Model":"Pilot","Year":"2008"}]
};

and then I can access data as:

$foo["data"][0]["make"]

With the help of the answers (and after getting the inside and outside loops correct) I got this to work:

var t = eval( "(" + request + ")" ) ;
for (var i = 0; i < t.data.length; i++) {
 myTable +=    "<tr>";
 for (var j = 0; j < t.hdrs.length; j++) {
  myTable += "<td>" ;
   if (t.data[i][t.hdrs[j]] == "") {myTable += "&nbsp;" ; }
    else { myTable += t.data[i][t.hdrs[j]] ; }
  myTable += "</td>";
 }
 myTable +=    "</tr>";
}