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JS multidimensional array spacefield

i wanna generate a 3x3 field. I want to do this with JS, it shall be a web application.
All fields shall inital with false. But it seems so that my code is not working correctly, but i don't find my fault. The goal is, that every spacesector is accessible.
Thats my idea:
// define size
var esize = generateSpace(3);
}

space[i] = false is replacing the array with a single boolean value false, not filling in all the entries in array you just created. You need another loop to initialize all the elements of the array.
function generateSpace(x) {
var space = [];
for (var i = 0; i < x; i++) {
space[i] = [];
for (var j = 0; j < x; j++) {
space[i][j] = false;
}
}
return space;
}
Also, your for() loop condition was wrong, as you weren't initializing the last element of space. It should have been i < space.length.
And when it's done, it needs to return the array that it created.

Since I got somewhat bored and felt like messing around, you can also initialize your dataset as shown below:
function generateSpace(x) {
return Array.apply(null, Array(x)).map(function() {
return Array.apply(null, Array(x)).map(function() {
return false;
});
});
}

The other functions work equally well, but here's a fairly simply looking one using ES6 that works for any square grid:
function generateSpace(x) {
return Array(x).fill(Array(x).fill(false));
}

What is use of $.map function in javascript?

Note: I just want to to understand what is $.map doing in following code..
I am working on openstack horizon,In one of the javascript file they are using $.map function Please seehorizon.d3linechar.js
My question is how $.map is works, what is $ before map. $.map is associated with javascript or jquery..
$.map(self.series, function(serie) {
serie.color = last_point_color = self.color(serie.name);
$.map(serie.data, function(statistic) {
// need to parse each date
statistic.x = d3.time.format.utc('%Y-%m-%dT%H:%M:%S').parse(statistic.x);
statistic.x = statistic.x.getTime() / 1000;
last_point = statistic;
last_point.color = serie.color;
});
});

Please read the jQuery documentation. Their are many many examples. Our folk is realy trying to help you. But what is the lack of your understanding in the $.map() function?
$ is only the namespace and makes at least the map function work. So forget about it.
map( input, outputFunction ) is iterating through the input which has to be an real array. The outputFunction, usually a self executing function, is able to manipulate the content of each element of the inputed array.
In your example:
$.map(self.series, function(serie) {
self.series is the input and each element of that array will be called as serie in the anonymous or rather self executed function.
serie.color = last_point_color = self.color(serie.name);
Change some color stuff...
$.map(serie.data, function(statistic) {
Next call of the mapping function.
// need to parse each date
statistic.x = d3.time.format.utc('%Y-%m-%dT%H:%M:%S').parse(statistic.x);
Parsing the date to a specific format like discribed in the comment.
statistic.x = statistic.x.getTime() / 1000;
Take the x value parse to a time or maybe to seconds and divide through 1000.
last_point = statistic;
Save element of serie.data to a temporar variable.
last_point.color = serie.color;
Save the color of the of the serie to the element of that serie.
});
});
All in all...
... $.map() iterates through self.series, then iterates through its children and then it looks like it changes the color of every single element to the color of that series.

$ is an alias for the jQuery object.
As for map(), it is an api function in jQuery used to convert the items in an array.
If you look at the source for map, the basic algorithm is to iterate over the passed in elems and obtain a converted value using the callback
function (elems, callback) {
var value, i = 0,
length = elems.length,
ret = [];
for (; i < length; i++) {
//alternatively, for objects, for (i in elems) {
value = callback(elems[i], i);
if (value != null) {
ret.push(value);
}
}
// Flatten any nested arrays
return concat.apply([], ret);
}

Looping data in javascript

How can I get the value BrandName in this image using javascript loop.

UPDATED: Since data variable you use to display the response is already a CartObject then use:
for (var i = 0, len = data.CartLists.length; i < len; i++) {
console.log( data.CartLists[i].Item.BrandName );
}

An alternative to the one VisioN said is the following:
for (var CartItemId in CartObject.CartLists) {
Console.log(CartObject.CartLists[CartItemId].Item.BrandName);
}
However, If you would attach an Prototype to the JSON object, you could obtain an Object in the for-loop instead of an Integer (Number).
for (var CartItem in CartObject.CarLists) {
Console.log(CartItem.Item.BrandName);
}
Note that if you are going to make everything right, you should insert the following in the for-loop:
if (CartObject.CarLists.hasOwnProperty(CartItem)) {
Console.log(CartItem.Item.BrandName);
}
This example will work, but as seen in the comments below. The use of it is not what it is designed for. The For-In loop is designed to loop over Object properties, not Array items.

Can I select 2nd element of a 2 dimensional array by value of the first element in Javascript?

I have a JSON response like this:
var errorLog = "[[\"comp\",\"Please add company name!\"],
[\"zip\",\"Please add zip code!\"],
...
Which I'm deserializing like this:
var log = jQuery.parseJSON(errorLog);
Now I can access elements like this:
log[1][1] > "Please add company name"
Question:
If I have the first value comp, is there a way to directly get the 2nd value by doing:
log[comp][1]
without looping through the whole array.
Thanks for help!

No. Unless the 'value' of the first array (maybe I should say, the first dimension, or the first row), is also it's key. That is, unless it is something like this:
log = {
'comp': 'Please add a company name'
.
.
.
}
Now, log['comp'] or log.comp is legal.

There are two was to do this, but neither avoids a loop. The first is to loop through the array each time you access the items:
var val = '';
for (var i = 0; i < errorLog.length; i++) {
if (errorLog[i][0] === "comp") {
val = errorLog[i][1];
break;
}
}
The other would be to work your array into an object and access it with object notation.
var errors = {};
for (var i = 0; i < errorLog.length; i++) {
errors[errorLog[i][0]] = errorLog[i][1];
}
You could then access the relevant value with errors.comp.
If you're only looking once, the first option is probably better. If you may look more than once, it's probably best to use the second system since (a) you only need to do the loop once, which is more efficient, (b) you don't repeat yourself with the looping code, (c) it's immediately obvious what you're trying to do.

No matter what you are going to loop through the array somehow even it is obscured for you a bit by tools like jQuery.
You could create an object from the array as has been suggested like this:
var objLookup = function(arr, search) {
var o = {}, i, l, first, second;
for (i=0, l=arr.length; i<l; i++) {
first = arr[i][0]; // These variables are for convenience and readability.
second = arr[i][1]; // The function could be rewritten without them.
o[first] = second;
}
return o[search];
}
But the faster solution would be to just loop through the array and return the value as soon as it is found:
var indexLookup = function(arr, search){
var index = -1, i, l;
for (i = 0, l = arr.length; i<l; i++) {
if (arr[i][0] === search) return arr[i][1];
}
return undefined;
}
You could then just use these functions like this in your code so that you don't have to have the looping in the middle of all your code:
var log = [
["comp","Please add company name!"],
["zip","Please add zip code!"]
];
objLookup(log, "zip"); // Please add zip code!
indexLookup(log, "comp"); // Please add company name!
Here is a jsfiddle that shows these in use.

Have you looked at jQuery's grep or inArray method?
See this discussion
Are there any jquery features to query multi-dimensional arrays in a similar fashion to the DOM?

Create an array with tree elements in Javascript

I need to create an array from tree elements in Javascript and being a newbie I don't know how to achieve this.
pseudo-code :
function make_array_of_tree_node(tree_node)
{
for (var i = 0; i < tree_node.childCount; i ++) {
var node = tree_node_node.getChild(i);
if (node.type ==0) {
// Here I'd like to put a link (node.title) in an array as an element
} else if (node.type ==6) {
// Here the element is a folder so a I need to browse it
make_array_of_tree_node(node)
}
}
}
// Some code
make_array_of_tree_node(rootNode);
// Here I'd like to have access to the array containing all the elements node.title

You can declare an array like this:
var nodes = [];
Then you can add things to it with:
nodes.push(something);
That adds to the end of the array; in that sense it's kind-of like a list. You can access elements by numeric indexes, starting with zero. The length of the array is maintained for you:
var len = nodes.length;
What you'll probably want to do is make the array another parameter of your function.
edit — To illustrate the pattern, if you've got a recursive function:
function recursive(data, array) {
if ( timeToStop ) {
array.push( data.whatever );
}
else {
recursive(data.subData, array);
}
}
Then you can use a second function to be the real API that other code will use:
function actual(data) {
var array = [];
recursive(data, array); // fills up the array
return array;
}
In JavaScript, furthermore, it's common to place the "recursive" function inside the "actual" function, which makes the recursive part private and keeps the global namespace cleaner.