Question

I have an object in my javascript which looks like this:

{"data":[{"t":{
                "level":"35",
                "longtitude":"121.050321666667",
                "latitude":"14.6215366666667",
                "color":"#040098"}},
         {"t":{
                "level":"31",
                "longtitude":"121.050316666667",
                "latitude":"14.621545",
                "color":"#040098"}},
         {"t":{
                "level":"29",
                "longtitude":"121.050323333333",
                "latitude":"14.62153",
                "color":"#040098"}},
//  .....

What I would like to do is to iterate thru the contents of my object so that I will be able to push them to their respective arrays independently.
I have an array for longitude, latitude, color and level.

So I have tried the following:

var size = 0, key;
for (key in result) {
    if (result.hasOwnProperty(key)) size++;
    alert(result.data[size]);
}

–>But this only alerts me “[object Object]”

success: function(result){
    var size = 0, key;
    for (key in result) {
        for(var attr in key){
            alert(attr['latitude']);
        }
    }
}

–>This gives me Undefined result[key]

I have checked that the size of my object is only 1 thru these codes

var size = 0, key;
for (key in result) {
    if (result.hasOwnProperty(key)) size++;
}
alert(size);        

I believe that only “data” is being read. And others that are inside “data” are disregarded.

I have read this, this, enter link description here, and this but they sall seem to deal with a different structure of objects. Thanks for the help in advanced.

UPDATE
Using the console.log(), I have confirmed, if im not mistaken that only the first attribute is being fetched

t
    Object { level="35", longtitude="121.0508", latitude="14.6204083333333", more...}
color       "#040098"
latitude    "14.6204083333333"
level       "35"
longtitude  "121.0508"

I tried this

for (key in result) {
            if (result.hasOwnProperty(key)) size++;
            console.log(result.data[size]['level']);
        }

–> but it says undefined

based on the structure of my object which is

data:[{"t":{'others'},'others'...]

How am I to read everything inside “data”? Each “data” has “t”.

Answer 1

Update: Using the for...in construct for iterating over arrays isn’t recommended. The alternative is a regular for loop (each method of course having their respective advantages):

for(var i=0; i<results.data.length; i++){
    alert(results.data[i]['t']['latitude']);
    // etc...
}

---

Be careful with the structure of your JSON. Also note that the javascript foreach loop iterates over keys/indices — not values. See demo: http://jsfiddle.net/g76tN/

success: function(result){
    var latitudes = [];
    // and so on...

    for (var idx in result.data ) {
        if( result.data.hasOwnProperty(idx) ){
            alert( result.data[idx]['t']['latitude'] );

            // So you would do something like this:
            latitudes.push ( result.data[idx]['t']['latitude'] );
            // and so on...
        }
    }
}​

Note for collecting properties of objects in an array, jQuery $.map() — or native js array map for that matter — is a neat, useful alternative.

var latitudes = $.map( result.data, function(n){
    return n['t']['latitude'];
});
// and so on...