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json object shows value 1

I am storing a json object in json array and assign it to another main json object, but when I print the value of main json object it display 1. Below is the code.
var jsonMainObject= {};
var jsonArray= [];
for(var j=0;j<cu.receivedData.length;j++) {
jsonMainObject["company"] = jsonArray.push(cu.receivedData[j].company);
}
console.log(jsonMainObject)
Below is the output
{ company: 1 }
But it should show the array. when i print jsonArray it shows the array of object, but when I console the output of jsonMainObject it displays the above output.

The push method returns the new length of the array. See documentation. I guess you should use:
jsonMainObject["company"].push(valueToPush)
or use concat (documentation)
jsonMainObject["company"] = jsonMainObject["company"].concat(valueToConcat)

There is no JSON at all here. JSON is a text format for representing data. What you have is a JavaScript object with a JavaScript array.
You are trying to put the array in the object at the same time as putting items in the array. The push method doesn't return the array that it was called on, it returns the length of the array. The company property will end up containing the length of the receivedData array.
You can put the array in the object from start:
var arr = [];
var mainObject = { company: arr };
for(var j = 0; j < cu.receivedData.length; j++) {
arr.push(cu.receivedData[j].company);
}
console.log(mainObject);

push value at index in array

I initialize my array as myArray=[]; I want to dynamically create an associative array in a for loop. I am trying to create a key index and push a new value in at the same time. I want each key index to be a number
like '1': '2': '3':
The number of indexes will be unknown so I need to create them in my loop
I am not sure how to accomplish this or push more values into each index. My code is:
var myArray=[];
for(i=0; i<10; i++){
myArray['1'].push(i);
myArray['2'].push(i);
myArray['3'].push(i);
}
alert(myArray);
There is an error in the code . I apologize if this is similar to a repeat question. I can not find this answer in my searches though. Thanks for any help.

You must initialize the subarrays in order to push. Better start with the index 0, tough.
var myArray = [[], [], []];
for(var i=0; i<10; i++){
myArray[0].push(i);
myArray[1].push(i);
myArray[2].push(i);
}

JavaScript arrays should be used with numeric indexes. If you want a map from string-valued keys to values, use a simple object:
var myMap = {};
To populate the map, you'll have to initialize the arrays for each key:
var myMap = { '1': [], '2': [], '3': [] };
Then your loop will work as-is.
edit — I may have misinterpreted your question. If you want your outer array to use just numeric indexes (I saw the strings and generalized, perhaps inappropriately) then you can indeed use an array of arrays:
var myMap = [ null, [], [], [] ];
(The first null is for index 0, which is implicitly where JavaScript array indexes start.)

Several things are wrong here:
#1
You want myArray to be an associative array, so as an object, it would be defined like so:
myArray = {};
#2
You cannot push() data in an array that has not been declared. Declare those arrays first:
myArray['1'] = [];
myArray['2'] = [];
myArray['3'] = [];
#3
You cannot directly alert() an array or an object. You need to get a string representation of it:
alert( JSON.stringify(myArray,null,4) ); // null,4 provides easy to read formating
JS Fiddle Demo

How to access multidimensional array by index in javascript?

I have an array like below in java-script
Result = [
{"ID":1,"Type":"Pyramid","Phase":"One"},
{"ID":2,"Type":"Pyramid","Phase":"Two"}
]
I tried accessing the individual values and was able to by the below code
alert(Result[0].ID) or alert(Result[0].Phase)
Is there a way to access this by index? like Result[0][1], i tried but getting [object][object]
also i need to access column count
Please help me

You have array of object and by using for loop you can easily access all element value.
try following
function getValue() {
var keys ;
var Result = [{"ID":1,"Type":"Pyramid","Phase":"One"}, {"ID":2,"Type":"Pyramid","Phase":"Two"}]
for(var i=0; i<Result.length;i++){
keys = [];
for(var k in Result[i]){
keys.push(k);
}
for(var k=0;k<keys.length;k++){
console.log(keys[k]+"="+ Result[i][keys[k]]);
}
console.log("key count =" +keys.length);
}
}
CHECK THIS

from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
alert(Result[0][Object.keys(Result[0])[0]]);
Result[0] gets the first row
Object.keys(Result[0]) gets the keys in the first row
Object.keys(Result[0])[0] gets the first column name.
Object.keys(Result[0]).length is the column count in the first row.
Also, objects are not indexed based on a linear integer index as arrays are, so assigning ordered numbers to the unordered list of keys is not right.
A two dimensional array would look like this:
Result = [
[1,"Pyramid","One"],
{2,"Pyramid","Two"}
]
in this case, you could address each field like so: Result[row][col] thus Result[0][2] would yield One.
To access fields in an array of object use the syntax you have provided. Also, why would you want to access the fields in your objects based on id? Or why would you not use an array of arrays?

Your Result is an array of object, then you must first get an object, and then get the property of your object. This is not a multidimensional array.

You array has an object we have to convert that object to array. So converting whole var Result to newResult you can access newResult and it's component through index number
Result = [
{"ID":1,"Type":"Pyramid","Phase":"One"},
{"ID":2,"Type":"Pyramid","Phase":"Two"}
];
var newResult = [];
for (var i = 0; i < Result.length; i++) {
newResult[i] = [];
for (var x in Result[i]) {
if (Result[i].hasOwnProperty(x)) {
newResult[i].push(Result[i][x]);
}
};
};
console.log(newResult);
Use newResult instead of Result
You can get ID by newResult[0][0]
http://jsfiddle.net/LLz1cbok/

Merge array into a single array

If this were .NET, I'd ask how to convert List<List<MyClass> to List<MyClass>. However, I'm not very good with javascript and don't know how to ask that as a question using Javascript terminology!
My javascript object comes through like
And is created as:
js_datasets.push({
"DataItem0": {
lzabel: "This",
data: [[1408710276000, null],[1408710276000, 15]]
},
"DataItem1": {
lzabel: "That",
data: [[1408710276000, null],[1408710276000, 15]]
},
});
js_datasets.push({
"DataItem22": {
lzabel: "And other",
data: [[1408710276000, null],[1408710276000, 5]]
},
"DataItem23": {
lzabel: "And lastly",
data: [[1408710276000, null],[1408710276000, 1]]
},
});
Each object is the same "type" (if it matters).
I'd like to create a single list but I am failing to do so. My efforts are
var myDataSet = []; //this is the results of what I want, ideally as a single list
for (var i = 0; i < js_datasets.length; i++) {
if (i==0) {
myDataSet.push(js_datasets[i]);
}
else {
myDataSet.concat(js_datasets[i]);//does nothing
myDataSet.join(js_datasets[i]);//does nothing
}
...more logic
As you can see with the above, I've tried using push, concat and join.
If I update the code to only use push (and never use concat and join) then I get all the values I want, but again, as an array within an array.
Using concat and join do not add to the list.
So, if we can assume the 12 items in the array (pictured) all contain 10 items, I'd like to have a single list of the 120 items!
How can I simply convert this multidimension array (is it multidimension) to a single dimension array.

This will be a bit complicated, as the items in your Array js_datasets are not Arrays, but a more generic Object. This means you can't assume the keys will be in order if you try to read them
Lets write some helper functions to account for this;
function dataItemCollectionToArray(o) {
var keys = Object.keys(o);
// assuming no non-DataItem keys, so next line commented out
// keys = keys.filter(function (e) {return e.indexOf("DataItem") === 0;});
keys.sort(function (a, b) { // ensure you will get the desired order
return +a.slice(8) - +b.slice(8);
});
return keys.map(function (e) {return o[e];});
}
Now you can loop over js_datasets performing this conversion
var myDataSet = [], i;
for (i = 0; i < js_datasets.length; ++i) {
// assuming no gaps, if you need to add gaps, also find min, max indices
// in `dataItemCollectionToArray`, and check them in each iteration here
myDataSet.push.apply(myDataSet, dataItemCollectionToArray(js_datasets[i]));
}
Please note that Object.keys and Array.prototype.map may require polifills if you wish to support old browsers, i.e. IE<=8
An easier solution however, may be to re-write how js_datasets is constructed so that the Objects you are pushing are more Array-like or indeed pushing true Arrays, perhaps with a couple extra properties so you know the offset for the first index. This would mean you can use flatten methods that you'll find around the internet

Javascript sort multi-dimensional array - a complete example?

I'm no Javascript expert and I'm having problems trying to glue together the various nuggets I find here and elsewhere regarding multi-dimensional arrays and sorting and wondered if someone could help me with a complete example?
I have managed to get to the point that I can populate a localStorage with data read in via Ajax.
The format of the rows is ...
(msgXXX) (Key1:Value1|Key2:Value2|Key3:Value3|...etc)
where
(msgXXX) is the localStorage key; and
(Key1:Value1|Key2:Value2|Key3:Value3|...etc) is the single concatenated localStorage data string
What I want to be able to do is convert all this to a multi-dimensional array to which I can apply various sorts. For example, one of the Keys is called "Timestamp" and the value is an integer representing seconds since the Unix epoch. I would like to sort all rows based on this Timestamp value (in descending order - ie latest first). Right now the dataset is just over 600 rows.
I'm comfortable I can do the extraction and slicing and dicing to get the data out of the localStorage, but I'm not even sure what I'm aiming for with regards to populating an array and then setting up the sort.
Can someone point me in the right direction?

You can go with something like this:
function create(line) {
var tokens = line.split("|");
var obj = {};
for (var i = 0; i < tokens.length; i++) {
tokens[i] = tokens[i].split(":");
obj[tokens[i][0]] = tokens[i][1];
}
return obj;
}
var arr = [];
for (....) { // iterate over the input that each line is of key/value format
arr.push(create(line));
}
function timestampSort(a, b) {
if (a == b)
return 0;
return a.timestamp < b.timestamp ? -1 : 1;
}
// to sort by timestamp
arr.sort(timestampSort);
This code creates an object per key/value line, in the format you gave. The object will have the keys as attributes. All of those objects are being pushed into an array, which is then being sorted by passing a compare function to the native sort method of array.
You can of course make as many compare functions as you want, each comparing by a different attribute/criteria.
You can read more about the sort method here: http://www.w3schools.com/jsref/jsref_sort.asp
EDIT
The sort method both changes the array itself and returns the array, so doing something like:
console.log(arr.sort(timestampSort));
Will both change the actual array and return it, and so the console.log will print it.
If you don't want to change the original array and have a copy of it that will get sorted you can:
var arr2 = arr.slice();
arr2.sort(timestampSort);
As for the keys in the array, what I wrote was intended to work only with this part of the line: Key1:Value1|Key2:Value2|Key3:Value3|...etc
So, to add support for the entire format, here's the modification:
function create(line) {
var parts = line.match(/^\(msg(\d+)\) \((.+)\)$/);
var tokens = parts[2].split("|");
var obj = { msgID: parts[1] };
for (var i = 0; i < tokens.length; i++) {
tokens[i] = tokens[i].split(":");
obj[tokens[i][0]] = tokens[i][1];
}
return obj;
}
If you apply this to the example you gave you'll get this:
arr is: [{
msgID: XXX,
Key1: Value1,
Key2: Value2,
Key3: Value3
}]
Hope this clears things for you.