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Get the lower integer id not already used in Javascript

I have a list of JS objects defined by an integer ID.
objects = [{
id: 0,
type: 'null'
}, {
id: 1,
type: 'foo'
}, {
id: 2,
type: 'bar'
}];
I implemented a function to remove an element from my list :
removeObject = function(o){
objects.splice(objects.indexOf(o), 1);
}
My problem is that I need to create a function to add a new item in my list with a id not already used (for example the lower positive integer not present in the list).
I tried to do something like that but it did not work when I remove the object 0 (for example).
addObject = function(type){
objects.push({
id: objects.length,
type: type
});
};
How can I do this ?
EDIT 1
According to your answers, I assume that the best solution in term of performance is to just use a topId which is always incremented when I add a new object in my list.
But that do not answer to my requierement. Actually I think that #X-Pippes response could be good.
Should I do someting like that :
objects = [{
id: 0,
type: 'null'
}, {
id: 1,
type: 'foo'
}, {
id: 2,
type: 'bar'
}];
// Init available ids list with the default value
availableIds = [objects.length];
removeObject = function(o){
// Remove the object from the list
objects.splice(objects.indexOf(o), 1);
// Add its id to the available ids list
availableIds.push(o.id);
}
addObject = function(type){
// Get lower id available
var newId = Math.min.apply(Math,availableIds);
// Push the new object with the id retrieved
objects.push({
id: newId,
type: type
});
// Remove used id from the available ids list
availableIds.splice(availableIds.indexOf(newId), 1);
// Add a default id if available list is empty
if(availableIds.length < 1) availableIds.push(objects.length);
};

if you remove for instance 0 and the next addObject is 0 you have to do something like:
keep a list [initial empty] with every ID removed. When you need to add a new one, pick the shorter, add and delete from list.
Also keep a var with the biggest ID added. If the previous list is empty, add +1 to the var and addObject with that id

Use the correct structures. A JavaScript object will do the job. It guarantees that you only get one item for key, you can look up and remove by key in probably O(1)ish. No point trying to re-implement it in a less efficient manner, which will be O(n) lookup.
var structure = {
objects : {},
topId : 0
}
structure.add = function(item) {
var id = this.topId ++;
structure.objects[id] = item;
}
structure.add("thing")
structure.add("other thing")
structure.add("another thing")
structure.objects
>>> Object {0: "thing", 1: "other thing", 2: "another thing"}
structure.objects[1]
>> "other thing"
Then the normal index operations to get/set/delete.
If you use that function then you have an invariant (guarantee) on your data structure that you won't use the same ID twice.

You need a function to find the first free number:
addObject = function(type){
objects.push({
id: firstOpenIndex(),
type: type
});
};
firstOpenIndex = function() {
for(var idx = 0; true; i++) {
var found = false;
for(var o in objects) {
if (objects[o].id == idx) {
found = true;
break;
}
}
if (!found) return idx;
}
}

In Javascript MaxInt is 9007199254740992. Why not just keep incrementing?

You can and probably should just use an array(s) like:
objects.type=['null','foo','bar'];
to add an object see:
How to append something to an array?
to find a value: var index = objects.type.indexOf('foo');
to find 1st empty field var index = objects.type.indexOf(''); which you can use to find the element for adding (if index is -1 use objects.type.length) if you "delete" an element by setting it to "" or... unless you have specific reason for keeping the "ID" static (in this case the array index), remove the element and only append new ones to the end
to remove an element see:
How do I remove a particular element from an array in JavaScript?
which will allow you to just push/append the next data.
if you need a new object array with empty fields to fill because you get new data to track:
object.newField=new Array(objects.type.length);
If you get to this point where your object contains multiple arrays, you will probably want to create functions for insert/add and delete/remove, so you don't do an operation on 1 and not the other.
Everything is already built in (read likely already pretty fast) and you don't need to reinvent constructors for your really cool object type.

jQuery add text before final element of an array

I have an array:
var countryArray = [];
That I'm dynamically inserting values to with click events:
(on click...)
countryArray.push("Australia");
and then finally appending to a div for output:
$('#summary-countries').append(countryArray+'');
So my output could be:
Australia,United Kingdom,Finland,Japan.
Is there any way how I could insert some text so that it would output as the following:
Australia,United Kingdom,Finland **AND** Japan.
Any help would be appreciated!

Here's one way:
var countries;
if( countryArray.length > 1 ) {
var last = countryArray.pop();
countries = countryArray.join(', ')+' and '+last;
}
else {
countries = ''+countryArray;
}
$( '#summary-countries' ).append( countries );

Yes, there is a way. You are relying on the built-in serialization of arrays, when you call .append(reasonsTravelling+'');. This converts reasonsTravelling into a string, which, by default is a comma separated list.
You have to use a for loop instead and go through all the items in the array. Once you find that the iterator is one before the last index, use the "And" instead of ",".
This fiddle should explain my idea: http://jsfiddle.net/v76Bf/

You can traverse through and array and find the last index and insert the text before the last value.
for (var i=0;i<countryArray.length;i++)
{
if(i==countryArray.length-1)
{
countryArray[i].join(,).push("And");
}
}

Delete an element inside a JSON array by value with jQuery

Part of my json Array
var videos = $j.parseJSON('
[
{ "privacy":"public",
"id":"1169341693" },
{ "privacy":"private",
"id":"803641223" },
{ "privacy":"public",
"id":"1300612600" }, ......
When I console.log the element I'm getting
[Object, Object, Object, …]
0: Object
privacy: "public"
id: "1169341693"
1: Object
privacy: "private"
id: "803641223"
2: Object
privacy: "public"
id: "1300612600"
I also have a unique id I want to search for
var uniqueId = 803641223;
I want to find, in my videos array, the right id, and delete that whole array element. So In that case, I want my final videos array to contain only 2 object, instead of 3 :
var videos = $j.parseJSON('
[
{ "privacy":"public",
"id":"1169341693" },
{ "privacy":"public",
"id":"1300612600" }, ......
My problem is how to get in the array to do my splice. I prefer to do it with jQuery
Any help please?

You can use grep :
videos = $.grep(videos, function(e) { return e.id!='803641223' });
In vanilla JavaScript you could have used the similar filter function but it's not supported by IE8.
Please note that videos is a JavaScript array, it's not a JSON array, even if it was made by parsing a JSON string.

A non-jQuery solution that modifies the array in place:
var uniqueId = 803641223;
var videos = [
{ "privacy":"public",
"id":"1169341693" },
{ "privacy":"private",
"id":"803641223" },
{ "privacy":"public",
"id":"1300612600" }
];
function cleaner(arr, id) {
for (var i = 0; i < videos.length; i++) {
var cur = videos[i];
if (cur.id == uniqueId) {
arr.splice(i, 1);
break;
}
}
}
cleaner(videos, uniqueId);
http://jsfiddle.net/4JAww/1/
Note that this modifies the original array in place, such that the original videos array will have the items you want, and the one that matched the uniqueId will be gone (forever). So it depends on whether you want to be able to access the original array ever again, or are okay with modifying it.
It just loops through the elements of the array, compares the item's id property to the uniqueId value, and splices if they match. I use break; immediately after the splice because you seem to imply that the uniqueId can/should only appear once in the array since it's...unique.

Hello you can remove element with javascript splice function...
videos.items.splice(1, 3); // Removes three items starting with the 2nd,

It worker for me.
arrList = $.grep(arrList, function (e) {
if(e.add_task == addTask && e.worker_id == worker_id) {
return false;
} else {
return true;
}
});
It returns an array without that object.
Hope it helps.

Backbone.js - Filter a Collection based on an Array containing multiple keywords

I'm using Backbone.js/Underscore.js to render a HTML table which filters as you type into a textbox. In this case it's a basic telephone directory.
The content for the table comes from a Collection populated by a JSON file.
A basic example of the JSON file is below:
[{
"Name":"Sales and Services",
"Department":"Small Business",
"Extension":"45446",
},
{
"Name":"Technical Support",
"Department":"Small Business",
"Extension":"18800",
},
{
"Name":"Research and Development",
"Department":"Mid Market",
"Extension":"75752",
}]
I convert the text box value to lower case and then pass it's value along with the Collection to this function, I then assign the returned value to a new Collection and use that to re-render the page.
filterTable = function(collection, filterValue) {
var filteredCollection;
if (filterValue === "") {
return collection.toJSON();
}
return filteredCollection = collection.filter(function(data) {
return _.some(_.values(data.toJSON()), function(value) {
value = (!isNaN(value) ? value.toString() : value.toLowerCase());
return value.indexOf(filterValue) >= 0;
});
});
};
The trouble is that the function is literal. To find the "Sales and Services" department from my example I'd have to type exactly that, or maybe just "Sales" or "Services". I couldn't type "sal serv" and still find it which is what I want to be able to do.
I've already written some javascript that seems pretty reliable at dividing up the text into an array of Words (now updated to code in use).
toWords = function(text) {
text = text.toLowerCase();
text = text.replace(/[^A-Za-z_0-9#.]/g, ' ');
text = text.replace(/[\s]+/g, ' ').replace(/\s\s*$/, '');
text = text.split(new RegExp("\\s+"));
var newsplit = [];
for (var index in text) {
if (text[index]) {
newsplit.push(text[index]);
};
};
text = newsplit;
return text;
};
I want to loop through each word in the "split" array and check to see if each word exists in one of the key/values. As long as all words exist then it would pass the truth iterator and get added to the Collection and rendered in the table.
So in my example if I typed "sal serv" it would find that both of those strings exist within the Name of the first item and it would be returned.
However if I typed "sales business" this would not be returned as although both the values do appear in that item, the same two words do not exist in the Name section.
I'm just not sure how to write this in Backbone/Underscore, or even if this is the best way to do it. I looked at the documentation and wasn't sure what function would be easiest.
I hope this makes sense. I'm a little new to Javascript and I realise I've dived into the deep-end but learning is the fun part ;-)
I can provide more code or maybe a JSFiddle if needed.

Using underscore's any and all make this relatively easy. Here's the gist of it:
var toWords = function(text) {
//Do any fancy cleanup and split to words
//I'm just doing a simple split by spaces.
return text.toLowerCase().split(/\s+/);
};
var partialMatch = function(original, fragment) {
//get the words of each input string
var origWords = toWords(original + ""), //force to string
fragWords = toWords(fragment);
//if all words in the fragment match any of the original words,
//returns true, otherwise false
return _.all(fragWords, function(frag) {
return _.any(origWords, function(orig) {
return orig && orig.indexOf(frag) >= 0;
});
});
};
//here's your original filterTable function slightly simplified
var filterTable = function(collection, filterValue) {
if (filterValue === "") {
return collection.toJSON();
}
return collection.filter(function(data) {
return _.some(_.values(data.toJSON()), function(value) {
return partialMatch(value, filterValue);
});
});
};
Note: This method is computationally pretty inefficient, as it involves first looping over all the items in the collection, then all the fields of each item, then all words in that item value. In addition there are a few nested functions declared inside loops, so the memory footprint is not optimal. If you have a small set of data, that should be OK, but if needed, there's a number of optimizations that can be done. I might come back later and edit this a bit, if I have time.
/code samples not tested

Display elements in my 2d Array in Javascript

I have a post function that returns a 2d array. How would I go about displaying each of the elements in it? My code looks something like this :
$.post("/Question/GetPollQuestionsForView/", { poll_ID: pollId }, function(result) {
//$("#CustomerList tbody").append($(result));
var myarray = new Array()
myarray = result;
alert(myarray);
});
what the alert returns is "System.String[][]". How can i go about appending each of the values from my array to my div tag called #divComparativeQuestions.

For example:
var data = new Array();
for(var i=0;i<myarray.length;i++){
data.push(myarray[i].join(', '));
}
$('#divComparativeQuestions').html(data.join('<br/>'));
(hope this works, not tested :), but you get the idea )

I'm guessing you want something like:
// given an array [[1,2],[3,4]] with a desired result of <div>1234</div>
$.post("/Question/GetPollQuestionsForView/", { poll_ID: pollId }, function(data) {
if(data) {
var div = $('#divComparativeQuestions');
$.each(data, function(index, element) {
div.append(element); // will be inner array of [1,2] or [3,4]
});
}
});
All pretty basic stuff, in this case I'm taking advantage of the fact js typically flattens array as strings without commas to get the desired out put, but if you want to delimit them items somehow or wrap them in tags or whatever, it's easy enough to work out by taking a few seconds to browse http://docs.jquery.com