Develop Reference

How to filter out objects if two keys are duplicate

const obj =
[
{
"id":"1",
"name":"a",
"email":"abc#gmail.com",
"expiryType":"premium"
},
{
"id":"2",
"name":"b",
"email":"abc#gmail.com",
"expiryType":"gold"
},
{
"id":"3",
"name":"b",
"email":"test#gmail.com",
"expiryType":"premium"
},
]
can somebody please help me how to filter out objects where email is same but i want to keep the one with expiry Type is premium ? How to achieve this using Javascript
Expected output would be
const obj =
[
{
"id":"1",
"name":"a",
"email":"abc#gmail.com",
"expiryType":"premium"
},
{
"id":"3",
"name":"b",
"email":"test#gmail.com",
"expiryType":"premium"
},
]

Assuming you want to keep the latest year's entry, you can keep a Map of the email addresses and years you've seen. See comments:
// The new list
const filtered = [];
// Known emails
const known = new Map();
// Loop through...
for (const entry of obj) {
// Get this email and expiry
const {email, expiryYear} = entry;
// Get the previous info if any
const previous = known.get(email);
if (previous) {
// If the previous one is older than this one,
// replace it with this one
if (previous.expiryYear < expiryYear) {
filtered[previous.index] = entry;
}
} else {
// Add this to the known list and the filtered array
known.set(email, {
index: filtered.length,
expiryYear
});
filtered.push(entry);
}
}
const obj = [
{
"id":"1",
"name":"a",
"email":"abc#gmail.com",
"expiryYear":"2020"
},
{
"id":"2",
"name":"a",
"email":"abc#gmail.com",
"expiryYear":"2019"
},
{
"id":"3",
"name":"b",
"email":"test#gmail.com",
"expiryYear":"2020"
},
];
// The new list
const filtered = [];
// Known emails
const known = new Map();
// Loop through...
for (const entry of obj) {
// Get this email and expiry
const {email, expiryYear} = entry;
// Get the previous info if any
const previous = known.get(email);
if (previous) {
// If the previous one is older than this one,
// replace it with this one
if (previous.expiryYear < expiryYear) {
filtered[previous.index] = entry;
}
} else {
// Add this to the known list and the filtered array
known.set(email, {
index: filtered.length,
expiryYear
});
filtered.push(entry);
}
}
console.log(filtered);
This has the advantage of not constantly re-scanning the new list for known entries.

You can filter out whole object based on unique key you want as below.
const obj =
[
{
"id": "1",
"name": "a",
"email": "abc#gmail.com",
"expiryType": "premium"
},
{
"id": "2",
"name": "b",
"email": "abc#gmail.com",
"expiryType": "gold"
},
{
"id": "3",
"name": "b",
"email": "test#gmail.com",
"expiryType": "premium"
}
]
function arrayUnique(arr, uniqueKey) {
const flagList = []
return arr.filter(function(item) {
if (flagList.findIndex(flagItem => flagItem[uniqueKey] === item[uniqueKey]) === -1) {
flagList.push(item)
return true
}
})
}
Method Calling....
let newObj = arrayUnique(obj,'email')
Output:
newObj = [
{
"id": "1",
"name": "a",
"email": "abc#gmail.com",
"expiryType": "premium"
},
{
"id": "3",
"name": "b",
"email": "test#gmail.com",
"expiryType": "premium"
}
]
Hope this helps.

You can do it simply with 2 loops. Maybe not the fastes but the simplest:
function deleteDouble(array, objectKey) {
for (var i = 0; i < array.length; i++) {
for (var j = 0; j < array.length; j++) {
if (i == j) {
continue;
}
if (array[i][objectKey] == array[j][objectKey]) {
array.splice(i, 1);
i = 0;
j = 0;
break;
}
}
}
return array;
}
deleteDouble(obj, "email");

javascript multi dimensional array

I am trying to create a multidimentional arrya in javascript where I can add items in the following fashion:
var foo = {
"Internal": {
"0":
{
"pic_id":"15011",
"description":"Picture of a cpu",
"localion":"img.cloudimages.us/2012/06/02/mycpu.png",
"type":"png"
},
"1":{
"pic_id":"15011",
"description":"Picture of a cpu",
"localion":"img.cloudimages.us/2012/06/02/mycpu.png",
"type":"png"
}
},
"External":
{
"0":
{
"pic_id":"15014",
"description":"Picture of a cpu",
"localion":"img.cloudimages.us/2012/06/02/mycpu.png",
"type":"png"
}
}
};
but I don't know how to get my value into the main category. I got the following code
vm.classificationNames = [,];
for (var i = 0; i < vm.classificationNames.length; i++) {
vm.allGroupsInClassifications.push(vm.classificationNames[i]);
}
for (var i = 0; i < data.length; i++) {
var item = data[i];
if (item.classification != null) {
} else if (item.classification == null) {
vm.classificationNames['Internal'][item];
}
}
console.log(vm.classificationNames);
I also tried to use the following without any luck:
vm.classificationNames['Internal'].push(item);
Does anyone know what I'd be doing wrong? thanks for the help in advance.

Thats because its an object, not an array.
Change your inner object to an array and push will work
var foo = {
"Internal": [ // <--- Note the square braces
{
"pic_id": "15011",
"description": "Picture of a cpu",
"localion": "img.cloudimages.us/2012/06/02/mycpu.png",
"type": "png"
},
{
"pic_id": "15011",
"description": "Picture of a cpu",
"localion": "img.cloudimages.us/2012/06/02/mycpu.png",
"type": "png"
}
], // <--- Note the square braces
"External": [ // <--- Note the square braces
{
"pic_id": "15014",
"description": "Picture of a cpu",
"localion": "img.cloudimages.us/2012/06/02/mycpu.png",
"type": "png"
}
] // <--- Note the square braces
};
foo['Internal'].push(item);

Try iterating over the dictionary with
for(var key in vm.classificationNames) {
var entry = vm.classificationNames[entry];
/*....*/

Compare two arrays and update with the new values by keeping the existing objects using javascript

Below are my two arrays .I want to compare them and the resultant array should contain the updated values.Id's are common..
The arrays spans to n levels ie., there is no fixed levels..
The first array ie., the array before updation..
var parentArray1=[
{
"id": 1,
"name": "test",
"context": [
{
"id": 1.1,
"name": "test 1.1"
}
]
},
{
"id": 2,
"name": "test"
},
{
"id": 3,
"name": "test",
"context": [
{
"id": 3.1,
"name": "test 3.1"
}
]
},
{
"id": 4,
"name": "test"
}
]
The operations that i performed are
1.Adding a new Item
2.Updating an existing item
As a result of these two operations the changed values I will be getting in a different array..
ie.,
var changedArray=
[
{
"id": 1,
"name": "test1",
"context": [
{
"id": 1.1,
"name": "Changed test 1.1"
}
]
},
{
"id": 5,
"name": "test5"
}
]
Now I have written a generic function that loops through the parentArray1 and using the unique propertiesI need to either add a new item,if the item is there in the changedArray or update an existing item at any level
The resultant array should be ..
[
{
"id": 1,
"name": "test",
"context": [
{
"id": 1.1,
"name": "Changed test 1.1"
}
]
},
{
"id": 2,
"name": "test"
},
{
"id": 3,
"name": "test",
"context": [
{
"id": 3.1,
"name": "test 3.1"
}
]
},
{
"id": 4,
"name": "test"
},
{
"id": 5,
"name": "test5"
}
]
Generic function:
compareArray(parentArray1, changedArray, ["id"]);
function compareArray(array1, array2, propertyArray) {
var newItem = new Array();
array2.map(function(a1Item) {
array1.map(function(a2Item) {
/ If array loop again /
if (a2Item.constructor === Array) {
compareArray(a2Item, a1Item)
} else {
/ loop the property name to validate /
propertyArray.map(function(property) {
if (a2Item[property]) {
if (a2Item[property] === a1Item[property]) {
a2Item = a1Item
} else {
var isAvailable = _.find(newItem, function(item) {
return item[property] === a1Item[property]
})
if (!isAvailable) {
newItem.push(a1Item);
}
}
}
})
}
});
});
/ Insert the new item into the source array /
newItem.map(function(item) {
array1.push(item);
});
console.log("After Compare : " + array1);
}

I suggest to use a temporary object for the reference to the id and update if exist or push if not exist.
var parentArray1 = [{ "id": 1, "name": "test", "context": [{ "id": 1.1, "name": "test 1.1" }] }, { "id": 2, "name": "test" }, { "id": 3, "name": "test", "context": [{ "id": 3.1, "name": "test 3.1" }] }, { "id": 4, "name": "test" }],
changedArray = [{ "id": 1, "name": "test1", "context": [{ "id": 1.1, "name": "Changed test 1.1" }] }, { "id": 5, "name": "test5" }];
function insert(array, data) {
function iter(array) {
array.forEach(function (a) {
if (!('id' in a)) {
return;
}
if (o[a.id] !== a) {
o[a.id] = a;
}
Object.keys(a).forEach(function (k) {
Array.isArray(a[k]) && iter(a[k]);
});
});
}
var o = {};
iter(array);
data.forEach(function (a) {
if (o[a.id]) {
Object.keys(a).forEach(function (k) {
o[a.id][k] = a[k];
});
return;
}
array.push(a);
});
}
insert(parentArray1, changedArray);
document.write('<pre>' + JSON.stringify(parentArray1, 0, 4) + '</pre>');

This is what I came up with:
function sameKeys(o1, o2, keys) {
for (var i = 0; i < keys.length; i++) {
var key = keys[i];
if (!o1.hasOwnProperty(key) || !o2.hasOwnProperty(key))
throw 'compared objects do not have the key ' + key;
if (o1[key] !== o2[key])
return false;
}
return true;
}
function isNothing(o) {
return typeof(o) === 'undefined' || o === null;
}
// this does not work if objects have functions as properties
function clone(o) {
if (isNothing(o))
return o;
return JSON.parse(JSON.stringify(o));
}
function extend(o1, o2, keys) {
if (isNothing(o2))
return;
if (isNothing(o1))
throw ('first parameter cannot be empty');
if (typeof(o1) != 'object' || typeof(o2) != 'object')
throw ('extend only works on objects');
Object.keys(o2).forEach(function (key) {
var newVal = o2[key];
if (o1.hasOwnProperty(key)) {
if (isNothing(newVal)) {
delete o1[key];
} else
if (Array.isArray(newVal)) {
compareArray(o1[key], newVal, keys);
} else {
switch (typeof(newVal)) {
case 'object':
extend(o1[key], newVal, keys);
break;
case 'boolean':
case 'number':
case 'string':
o1[key] = newVal;
break;
default:
throw 'not supported property type: ' + typeof(newVal);
}
}
} else {
o1[key] = clone(newVal);
}
});
}
function removeFromArray(arr, ids, keyArray) {
var indexes = [];
var it1s = arr.forEach(function (it, idx) {
if (sameKeys(ids, it, keyArray)) {
indexes.push(idx);
} else {
Object.keys(it).forEach(function (key) {
var newVal = it[key];
if (Array.isArray(newVal)) {
removeFromArray(it[key], ids, keyArray);
}
});
}
});
if (indexes.length) {
if (indexes.length > 1)
throw 'found multiple possible objects for the same key combination'
arr.splice(indexes[0], 1);
}
}
function compareArray(a1, a2, keyArray) {
a2.forEach(function (it2) {
var it1s = a1.filter(function (it) {
return sameKeys(it2, it, keyArray);
});
var it1;
if (!it1s.length) {
it1 = clone(it2);
a1.push(it1);
} else {
if (it1s.length > 1)
throw 'found multiple possible objects for the same key combination'
it1 = it1s[0];
extend(it1, it2, keyArray);
}
if (it2.removedIds) {
it2.removedIds.forEach(function (ids) {
removeFromArray(a1, ids, keyArray);
});
}
});
}
Use it with compareArray(parentArray1,changedArray,['id']);
Note that it would not work with objects that contain functions. Also, if the arrays would be large, perhaps a better solution is to sort both arrays by key, then always look from the last found object up. That's all I got for now.
Updated it with some concepts from Nina and some clearing of the code.
As I understood it, you only want to add properties. So extend({a: {b: 2}},{a:{c:3}}) will result in {a: {b:2,c:3}}. If this is not what you wanted, let me know.
I also added functionality for removing ids. If any of the objects in the array contains a removedIds array of the form [{id: 4},{id: 5}] then the items with those ids will be removed from the original array.

Slight modification on code, to satisfy your conditions. Try it!
function compareArray(originalArray, destinationArray, propertyArray) {
var newItem = new Array(), processedItem = new Array();
for (var i = 0; i < originalArray.length; i++) {
var sourceElement = originalArray[i];
for (var j = 0; j < destinationArray.length; j++) {
var destinationElement = destinationArray[j];
var isUpdated = false;
if (sourceElement.constructor === Array) {
compareArray(sourceElement, destinationElement, propertyArray);
} else {
/* loop the property name to validate */
propertyArray.map(function(property) {
if (sourceElement[property]) {
if (sourceElement[property] === destinationElement[property]) {
originalArray[i] = _.clone(destinationElement);
isUpdated = true;
return;
} else {
var isAvailable = _.find(newItem, function(item) {
return item[property] === destinationElement[property];
});
if (!isAvailable) {
var isAlreadyProcessed = _.find(processedItem, function(item) {
return item[property] === destinationElement[property];
});
if(!isAlreadyProcessed){
newItem.push(destinationElement);
}
}
}
}
});
}
if (isUpdated === true) {
break;
}
}
processedItem.push(sourceElement);
}
newItem.map(function(item) {
originalArray.push(item);
});
return originalArray;
}

filter result using 2 JSON

This is my saved localstorage,
[{"industry_Id":1,"merchant_id":2}]
I want to filter below result, to get HP.
{
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
}
I thought of using multiple $.each but it have to iterate few times and it's quite redundant.

I would prefer using Javascript for loop, that way you can skip iterating over every object once required element is found.
Without jQuery (using for)
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
With jQuery (using $.each)
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
var arg = [{"industry_Id":1,"merchant_id":2}];
var data = {
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
};
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
console.log(merchant);
document.writeln("<b>Without jQuery:</b><br>");
document.writeln((merchant !== null) ? "Found " + merchant['name'] : "Not found");
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
console.log(merchant_found);
document.writeln("<br><br><b>With jQuery:</b><br>");
document.writeln((merchant_found) ? "Found " + merchant_found['name'] : "Not found");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

selectors.map(function(selector) {
return data.industries.filter(function(industry) {
return industry.id == selector.industry_Id;
})[0].merchant.filter(function(merchant) {
return merchant.id == selector.merchant_id;
})[0].name;
});
// => DEF
If you want "HP", you want industry 2, not industry 1.
.filter(...)[0] is not really optimal. You could use .find(...), but that is not yet universally supported. Or you could use plain old JavaScript and write for loops instead to make it fast. Or you could use objects with ID keys instead of arrays to make lookups faster.

When it comes into a position where collection of data is what you're processing, I suggest you to take a look at underscore.js. It's not optimal choice for the best performance but it does make you code more readable and makes more sense especially when compared with loop.
Say data is a variable which stores your JSON data.
Try this:
// Given this selector criteria
var select = [{"industry_Id":1,"merchant_id":2}];
function filterByCriteria(criteria, data){
var match = [];
_.each(criteria, function(crit){
function matchIndustry(rec){ return rec.id===crit.industry_Id }
function matchMerchant(rec){ return rec.id===crit.merchant_id }
// Filter by industry id
var industry = _.first(_.where(data.industry, matchIndustry));
// Filter by merchant id
var merchant = _.where(industry.merchant, matchMerchant);
_.each(merchant, function addToMatchResult(m){
match.push(m.name);
});
});
return match;
}
var filteredData = filterByCriteria(select, data);
From snippet above, any merchants which match the search criteria will be taken to the match list. Is it more readable to you?

Do you even need numerical id's? Gets super easy when you don't.
/*
{
"industry": {
"oil and gas":{
"merchant": {
"ABC": {
"name": "ABC oil"
},
"DEF": {
"name": "DEF gas"
},
"GHJ" :{
"name": "GHJ oil and gas"
}
}
},
"IT": {
"merchant": {
"Apple" : {
"name": "Apple computers"
},
"HP": {
"name": "Hewlett Packard"
},
"Google": {
"name": "Google. Maw haw haw"
}
}
}
}
}
*/
var data = '{"industry": {"oil and gas":{"merchant": {"ABC": {"name": "ABC oil"},"DEF": {"name": "DEF gas"},"GHJ" :{"name": "GHJ oil and gas"}}},"IT": {"merchant": {"Apple" : {"name": "Apple computers"},"HP": {"name": "Hewlett Packard"},"Google": {"name": "Google. Maw haw haw"}}}}}';
data = JSON.parse(data);
var merchant = data.industry['IT'].merchant['HP'];
alert(merchant.name);
//console.log(merchant.name);

How to iterate through nested objects in a generic way

I am trying to fetch the value of the nested objects without using it's key. Like for example if I have a object like
var a = {"key" : "100"}
I don't want to use a.key, to get the result, though i have nested objects, it is becoming difficult for me to fetch the value this is what I have tried:
var Obj = [{"ghi":{"content":"abc"}},{"def":{"imgURL":"test.png"}},{"abc":{"key":"001"}},{"ghi":{"content":"abc"}},{"def":{"imgURL":"test.png"}},{"abc":{"key":"001"}}]
for(var key in Obj){
abc = Obj[key]
for(var j in abc){
def = abc[key]
}
}
So i need the values of all the objects, without using the key directly.

Maybe this helps
function getValues(array, key) {
var result = [];
array.forEach(function (a) {
a[key] && result.push(a[key]);
});
return result;
}
var array = [{ "ghi": { "content": "abc" } }, { "def": { "imgURL": "test.png" } }, { "abc": { "key": "001" } }, { "ghi": { "content": "abc" } }, { "def": { "imgURL": "test.png" } }, { "abc": { "key": "001" } }];
document.write('<pre>' + JSON.stringify(getValues(array, 'ghi'), 0, 4) + '</pre>');