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How to save distinct values in an object in javascript?

I have a bunch of log data which is stored in a variable. Each log value contains a camera name and system ip. I want to create an object which has names as all the distinct system ip's and corresponding value as an array which contains all the camera names corresponding to that system ip. Below is my code ---
$http(req).success(function(data){
$scope.logs = data;
$scope.cameras={};
var v =$scope.logs[0].systemIp;
$scope.cameras["v"]=[];
$scope.cameras["v"].push($scope.logs[0].cameraName);
for(i=1;i<$scope.logs.length;i++){
v=$scope.logs[i].systemIp;
var flag=0;
for(j in $scope.cameras){
if(j==="v")
{
flag=1;
break;
}
}
if(flag==0)
{
$scope.cameras["j"]=[];
$scope.cameras["j"].push($scope.logs[i].cameraName);
}
else if(flag==1)
{
$scope.cameras["v"].push($scope.logs[i].cameraName);
}
}});
And this is what my data looks like --
[{
"_id": "57683fd82c77bb5a1a49a2aa",
"cameraIp": "192.16.0.9",
"cameraName": "garage2",
"systemIp": "192.168.0.2"
},
{
"_id": "57683f8e2c77bb5a1a49a2a9",
"cameraIp": "192.16.0.8",
"cameraName": "garage1",
"systemIp": "192.168.0.2"
},
{
"_id": "57683f5e2c77bb5a1a49a2a8",
"cameraIp": "192.16.0.7",
"cameraName": "Back Door",
"systemIp": "192.168.0.4"
}]
When I print $scope.cameras on my console it gives this as the output -
Object { v: Array[3] }
I want by cameras object to look like this --
{ "192.168.0.2" : [ "garage1" , "garage2"] ,
"192.168.0.4" : [ "Back Door"] }
I am new to javascript, any help is appreciated.

If you are using the Lodash or Underscore library (which I highly recommend), you can just use the _.groupBy() function to do what you are after (along with some other functions to ensure all values are unique).
However, you can also easily implement it yourself:
function groupByDistinct(arr, prop, mapFn) {
mapFn = mapFn || function (x) { return x; };
var output = {};
arr.forEach(function (item) {
var key = item[prop],
val = mapFn(item);
if (!output[key]) {
output[key] = [val];
return;
}
if (output[key].indexOf(val) < 0) {
output[key].push(val);
}
});
return output;
}
Use it for your code like so:
$scope.cameras = groupByDistinct(data, 'cameraIp', function (logEntry) {
return logEntry.cameraName;
});

You are passing a string such as "v" or "j" as your object key, and this string are actually ending being your object key and not the value of this variables as you want. You can use something like this:
for(i=0; i < $scope.logs.length; i++){
var _sysIp = $scope.logs[i].systemIp,
_camName = $scope.logs[i].cameraName;
if(!$scope.cameras.hasOwnProperty(_sysIp)) {
$scope.cameras[_sysIp] = [_camName];
} else if ($scope.cameras[_sysIp].indexOf(_camName) < 0) {
$scope.cameras[_sysIp].push(_camName);
}
}

Better way to transform a collection using underscorejs

I'm trying to simply replace the invalid date with an empty string. I'm iterating through an array of objects, but whenever I try to use _.each() I get lost. If someone could show me a way to iterate through all the fieldsToCheck items in my list, that would be rad.
massage.removeBadDates = function(data){
var fieldsToCheck = [
"partsLeadTime",
"statusDate",
"targetDate",
"revisedTargetDate",
"quoteDate",
"dispositionDate",
"serviceDate",
"finalDate",
"receivedDate"]
var newData = []
_.map(data, function(value, index, list){
newData.push(value)
//single
if (list[index].partsLeadTime == "1900-01-01T00:00:00"){
newData[index].partsLeadTime = ""
}
});
return newData
};

You pretty much want something like this:
_.each(fieldsToCheck(function(field) {
if (list[index][field] == "1900-01-01T00:00:00") {
newData[index][field] = ""
}
});

Json Filtering in jquery

Hello i want to filter json data like sql query without the help of plugins like alasql.js or linq.js or any plugins.
for example
{
"Managing PCL": [
{
"idItScreen": "1436",
"topicName": "Managing PCL",
"isFav": 0,
"cdeItScreen": "ListActiveTarif",
"busScreenName": "My Current Tarif"
},
{
"idItScreen": "1437",
"topicName": "Managing PCL",
"isFav": 0,
"cdeItScreen": "ListTermineTarif",
"busScreenName": "History Tarif"
}
]
}
for example i need to get data where idItScreen>1430 so that json data must be displayed the main challenge is to do without plugins so please reccomend me a good solution to do this without plugins

First turn your JSON into a Javascript object:
var obj = JSON.parse(myJSON);
Then do your filtering:
var matches = [];
var arr = obj['Managing PCL'];
for (var i = 0; i < arr.length; i++) {
if (arr[i].idItScreen > 1430) {
matches.push(arr[i]);
}
}
Or using jQuery.grep:
var matches = jQuery.grep(obj['Managing PCL'], function(n, i) {
return n.idItScreen > 1430;
});
Now matches contains the matching items.
If you want to get the JSON again, just use JSON.stringify:
var filteredJSON = JSON.stringify({'Managing PCL': matches});

You can also simply use .filter:
var matches = [];
var all = obj['Managing PCL'];
var filtered = all.filter(function(){
return $(this).idItScreen > 1430;
})

You don't need to use jQuery for this. You can use the filter() method of Array.prototype. See the working snippet below:
var obj = {
"Managing PCL": [{
"idItScreen": "1436",
"topicName": "Managing PCL",
"isFav": 0,
"cdeItScreen": "ListActiveTarif",
"busScreenName": "My Current Tarif"
}, {
"idItScreen": "1437",
"topicName": "Managing PCL",
"isFav": 0,
"cdeItScreen": "ListTermineTarif",
"busScreenName": "History Tarif"
}]
};
var filteredArray = obj['Managing PCL'].filter(function(item) {
return item.idItScreen > 1430;
});
obj['Managing PCL'] = filteredArray;
document.getElementById('result').innerHTML = JSON.stringify(obj);
<div id="result"></div>

You don't need jQuery for this. Use filter on the data instead.
function filterData(data, key, value) {
return data.filter(function (el) {
return el[key] > value;
});
}
// Note, `filter` operates on arrays, so you need to specify the
// array that contains the data
var result = filterData(data['Managing PCL'], 'idItScreen', '1430');
Also note that filter returns a new array containing the objects that it's found that match your criteria. You can access those objects in the usual way: result[0], for example.
DEMO
You could even expand this to create a function that returns data based on the operator too, not just greater-than, by using a look-up object:
var lookup = {
'>': function (data, value) { return data > value; },
'<': function (data, value) { return data < value; },
'===': function (data, value) { return data === value; }
}
function filterData(data, key, operator, value) {
return data.filter(function (el) {
return lookup[operator](el[key], value);
});
}
filterData(data['Managing PCL'], 'idItScreen', '>', '1430');
filterData(data['Managing PCL'], 'idItScreen', '===', '1430');
DEMO

Reconstruct JSON after duplicates have been removed

I have the following JSON -
{
"node1":[
{
"one":"foo",
"two":"foo",
"three":"foo",
"four":"foo"
},
{
"one":"bar",
"two":"bar",
"three":"bar",
"four":"bar"
},
{
"one":"foo",
"two":"foo",
"three":"foo",
"four":"foo"
}
],
"node2":[
{
"link":"baz",
"link2":"baz"
},
{
"link":"baz",
"link2":"baz"
},
{
"link":"qux",
"link2":"qux"
},
]
};
I have the following javascript that will remove duplicates from the node1 section -
function groupBy(items, propertyName) {
var result = [];
$.each(items, function (index, item) {
if ($.inArray(item[propertyName], result) == -1) {
result.push(item[propertyName]);
}
});
return result;
}
groupBy(catalog.node1, 'one');
However this does not account for dupicates in node2.
The resulting JSON I require is to look like -
{
"node1":[
{
"one":"foo",
"two":"foo",
"three":"foo",
"four":"foo"
},
{
"one":"bar",
"two":"bar",
"three":"bar",
"four":"bar"
}
],
"node2":[
{
"link":"baz",
"link2":"baz"
},
{
"link":"qux",
"link2":"qux"
},
]
};
However I cannot get this to work and groupBy only returns a string with the duplicates removed not a restructured JSON?

You should probably look for some good implementation of a JavaScript set and use that to represent your node objects. The set data structure would ensure that you only keep unique items.
On the other hand, you may try to write your own dedup algorithm. This is one example
function dedup(data, equals){
if(data.length > 1){
return data.reduce(function(set, item){
var alreadyExist = set.some(function(unique){
return equals(unique, item);
});
if(!alreadyExist){
set.push(item)
}
return set;
},[]);
}
return [].concat(data);
}
Unfortunately, the performance of this algorithm is not too good, I think somewhat like O(n^2/2) since I check the set of unique items every time to verify if a given item exists. This won't be a big deal if your structure is really that small. But at any rate, this is where a hash-based or a tree-based algorithm would probably be better.
You can also see that I have abstracted away the definition of what is "equal". So you can provide that in a secondary function. Most likely the use of JSON.stringify is a bad idea because it takes time to serialize an object. If you can write your own customized algorithm to compare key by key that'd be probably better.
So, a naive (not recommended) implementation of equals could be somewhat like the proposed in the other answer:
var equals = function(left, right){
return JSON.stringify(left) === JSON.stringify(right);
};
And then you could simply do:
var res = Object.keys(source).reduce(function(res, key){
res[key] = dedup(source[key], equals);
return res;
},{});

Here is my version:
var obj = {} // JSON object provided in the post.
var result = Object.keys(obj);
var test = result.map(function(o){
obj[o] = obj[o].reduce(function(a,c){
if (!a.some(function(item){
return JSON.stringify(item) === JSON.stringify(c); })){
a.push(c);
}
return a;
},[]); return obj[o]; });
console.log(obj);//outputs the expected result
Using Array.prototype.reduce along with Array.prototype.some I searched for all the items being added into the new array generated into Array.prototype.reduce in the var named a by doing:
a.some(function(item){ return JSON.stringify(item) === JSON.stringify(c); })
Array.prototype.some will loop trough this new array and compare the existing items against the new item c using JSON.stringify.

Try this:
var duplicatedDataArray = [];
var DuplicatedArray = [];
//Avoiding Duplicate in Array Datas
var givenData = {givenDataForDuplication : givenArray};
$.each(givenData.givenDataForDuplication, function (index, value) {
if ($.inArray(value.ItemName, duplicatedDataArray) == -1) {
duplicatedDataArray.push(value.ItemName);
DuplicatedArray.push(value);
}
});

how to get distinct values from json in jquery

I've got a jquery json request and in that json data I want to be able to sort by unique values. so I have
{
"people": [{
"pbid": "626",
"birthDate": "1976-02-06",
"name": 'name'
}, {
"pbid": "648",
"birthDate": "1987-05-22",
"name": 'name'
}, .....
So, far, i have this
function(data) {
$.each(data.people, function(i, person) {
alert(person.birthDate);
})
}
but, I am at a total loss as to how efficiently get only the unique birthDates, and sort them by year (or any sort by any other personal data).
I'm trying to do this, and be efficient about it (i'm hoping that is possible).
Thanks

I'm not sure how performant this will be, but basically I'm using an object as a key/value dictionary. I haven't tested this, but this should be sorted in the loop.
function(data) {
var birthDates = {};
var param = "birthDate"
$.each(data.people, function() {
if (!birthDates[this[param]])
birthDates[this[param]] = [];
birthDates[this[param]].push(this);
});
for(var d in birthDates) {
// add d to array here
// or do something with d
// birthDates[d] is the array of people
}
}

function(data){
var arr = new Array();
$.each(data.people, function(i, person){
if (jQuery.inArray(person.birthDate, arr) === -1) {
alert(person.birthDate);
arr.push(person.birthDate);
}
});
}

Here's my take:
function getUniqueBirthdays(data){
var birthdays = [];
$.each(data.people, function(){
if ($.inArray(this.birthDate,birthdays) === -1) {
birthdays.push(this.birthDate);
}
});
return birthdays.sort();
}