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How to convert array of object into an array of object with different format?

I'm having an array of object,in which I'm storing the billkey and billvalue as attributes. I want billkey to be the key and billvalue to be the value of that particular key.
var log=[
{
billkey:"Name",
billvalue:"ABC"
},
{
billkey:"Department",
billvalue:"Computer"
}
{
billkey:"Name",
billvalue:"XYZ"
},
{
billkey:"Department",
billvalue:"Electrical"
}];
And I want to convert it into this format:
var log=[
{
Name:"ABC",
Department:"Computer"
},
{
Name:"XYZ",
Department:"Electrical"
}];

How about this simple solution. Hope it helps!
var log=[
{
billkey:"Name",
billvalue:"ABC"
},
{
billkey:"Department",
billvalue:"Computer"
},
{
billkey:"Name",
billvalue:"XYZ"
},
{
billkey:"Department",
billvalue:"Electrical"
}];
var arr = [];
var finalObj = [];
for(var i in log){
var someObject = log[i];
for(var j in someObject){
arr.push(someObject[j]);
}
}
for(var k = 0; k < arr.length; k+=4){
finalObj.push({
Name: arr[k+1],
Department: arr[k+3]
});
}
console.log(finalObj);

create the result using forloop
// store the values
var logs=[];
var log=[
{
billkey:"Name",
billvalue:"ABC"
},
{
billkey:"Department",
billvalue:"Computer"
},
{
billkey:"Name",
billvalue:"XYZ"
},
{
billkey:"Department",
billvalue:"Electrical"
},
];
loop the first array
for (i = 0; i < log.length; i++) {
// create empty variable for storing the values
var index = new Array();
// insert the first index value to key
index[log[i].billkey] = log[i].billvalue
// insert the second index value to key
index[log[i+1].billkey] = log[i+1].billvalue
// insert the result in to new array
logs.push(index);
// increment the i with 1
i=i+1;
}
console.log(logs);

You could use Array#reduce and use the remainder operator as witch for using either the last object or create a new one.
var log = [{ billkey: "Name", billvalue: "ABC" }, { billkey: "Department", billvalue: "Computer" }, { billkey: "Name", billvalue: "XYZ" }, { billkey: "Department", billvalue: "Electrical" }],
result = log.reduce(function (r, a, i) {
var o = {};
if (i % 2) {
r[r.length - 1][a.billkey] = a.billvalue;
} else {
o[a.billkey] = a.billvalue;
r.push(o);
};
return r;
}, []);
console.log(result);

How can I check if the array of objects have duplicate property values?

I need some help with iterating through array, I keep getting stuck or reinventing the wheel.
values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName1' },
{ name: 'someName1' }
]
How could I check if there are two (or more) same name value in array? I do not need a counter, just setting some variable if array values are not unique. Have in mind that array length is dynamic, also array values.

Use array.prototype.map and array.prototype.some:
var values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName4' },
{ name: 'someName2' }
];
var valueArr = values.map(function(item){ return item.name });
var isDuplicate = valueArr.some(function(item, idx){
return valueArr.indexOf(item) != idx
});
console.log(isDuplicate);

ECMA Script 6 Version
If you are in an environment which supports ECMA Script 6's Set, then you can use Array.prototype.some and a Set object, like this
let seen = new Set();
var hasDuplicates = values.some(function(currentObject) {
return seen.size === seen.add(currentObject.name).size;
});
Here, we insert each and every object's name into the Set and we check if the size before and after adding are the same. This works because Set.size returns a number based on unique data (set only adds entries if the data is unique). If/when you have duplicate names, the size won't increase (because the data won't be unique) which means that we would have already seen the current name and it will return true.
ECMA Script 5 Version
If you don't have Set support, then you can use a normal JavaScript object itself, like this
var seen = {};
var hasDuplicates = values.some(function(currentObject) {
if (seen.hasOwnProperty(currentObject.name)) {
// Current name is already seen
return true;
}
// Current name is being seen for the first time
return (seen[currentObject.name] = false);
});
The same can be written succinctly, like this
var seen = {};
var hasDuplicates = values.some(function (currentObject) {
return seen.hasOwnProperty(currentObject.name)
|| (seen[currentObject.name] = false);
});
Note: In both the cases, we use Array.prototype.some because it will short-circuit. The moment it gets a truthy value from the function, it will return true immediately, it will not process rest of the elements.

In TS and ES6 you can create a new Set with the property to be unique and compare it's size to the original array.
const values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName3' },
{ name: 'someName1' }
]
const uniqueValues = new Set(values.map(v => v.name));
if (uniqueValues.size < values.length) {
console.log('duplicates found')
}

To know if simple array has duplicates we can compare first and last indexes of the same value:
The function:
var hasDupsSimple = function(array) {
return array.some(function(value) { // .some will break as soon as duplicate found (no need to itterate over all array)
return array.indexOf(value) !== array.lastIndexOf(value); // comparing first and last indexes of the same value
})
}
Tests:
hasDupsSimple([1,2,3,4,2,7])
// => true
hasDupsSimple([1,2,3,4,8,7])
// => false
hasDupsSimple([1,"hello",3,"bye","hello",7])
// => true
For an array of objects we need to convert the objects values to a simple array first:
Converting array of objects to the simple array with map:
var hasDupsObjects = function(array) {
return array.map(function(value) {
return value.suit + value.rank
}).some(function(value, index, array) {
return array.indexOf(value) !== array.lastIndexOf(value);
})
}
Tests:
var cardHand = [
{ "suit":"spades", "rank":"ten" },
{ "suit":"diamonds", "rank":"ace" },
{ "suit":"hearts", "rank":"ten" },
{ "suit":"clubs", "rank":"two" },
{ "suit":"spades", "rank":"three" },
]
hasDupsObjects(cardHand);
// => false
var cardHand2 = [
{ "suit":"spades", "rank":"ten" },
{ "suit":"diamonds", "rank":"ace" },
{ "suit":"hearts", "rank":"ten" },
{ "suit":"clubs", "rank":"two" },
{ "suit":"spades", "rank":"ten" },
]
hasDupsObjects(cardHand2);
// => true

if you are looking for a boolean, the quickest way would be
var values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName1' },
{ name: 'someName1' }
]
// solution
var hasDuplicate = false;
values.map(v => v.name).sort().sort((a, b) => {
if (a === b) hasDuplicate = true
})
console.log('hasDuplicate', hasDuplicate)

const values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName4' },
{ name: 'someName4' }
];
const foundDuplicateName = values.find((nnn, index) =>{
return values.find((x, ind)=> x.name === nnn.name && index !== ind )
})
console.log(foundDuplicateName)
Found the first one duplicate name
const values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName4' },
{ name: 'someName4' }
];
const foundDuplicateName = values.find((nnn, index) =>{
return values.find((x, ind)=> x.name === nnn.name && index !== ind )
})

You just need one line of code.
var values = [
{ name: 'someName1' },
{ name: 'someName2' },
{ name: 'someName4' },
{ name: 'someName2' }
];
let hasDuplicates = values.map(v => v.name).length > new Set(values.map(v => v.name)).size ? true : false;

Try an simple loop:
var repeat = [], tmp, i = 0;
while(i < values.length){
repeat.indexOf(tmp = values[i++].name) > -1 ? values.pop(i--) : repeat.push(tmp)
}
Demo

With Underscore.js A few ways with Underscore can be done. Here is one of them. Checking if the array is already unique.
function isNameUnique(values){
return _.uniq(values, function(v){ return v.name }).length == values.length
}
With vanilla JavaScript
By checking if there is no recurring names in the array.
function isNameUnique(values){
var names = values.map(function(v){ return v.name });
return !names.some(function(v){
return names.filter(function(w){ return w==v }).length>1
});
}

//checking duplicate elements in an array
var arr=[1,3,4,6,8,9,1,3,4,7];
var hp=new Map();
console.log(arr.sort());
var freq=0;
for(var i=1;i<arr.length;i++){
// console.log(arr[i-1]+" "+arr[i]);
if(arr[i]==arr[i-1]){
freq++;
}
else{
hp.set(arr[i-1],freq+1);
freq=0;
}
}
console.log(hp);

You can use map to return just the name, and then use this forEach trick to check if it exists at least twice:
var areAnyDuplicates = false;
values.map(function(obj) {
return obj.name;
}).forEach(function (element, index, arr) {
if (arr.indexOf(element) !== index) {
areAnyDuplicates = true;
}
});
Fiddle

Adding updated es6 function to check for unique and duplicate values in array. This function is modular and can be reused throughout the code base. Thanks to all the post above.
/* checks for unique keynames in array */
const checkForUnique = (arrToCheck, keyName) => {
/* make set to remove duplicates and compare to */
const uniqueValues = [...new Set(arrToCheck.map(v => v[keyName]))];
if(arrToCheck.length !== uniqueValues.length){
console.log('NOT UNIQUE')
return false
}
return true
}
let arr = [{name:'joshua'},{name:'tony'},{name:'joshua'}]
/* call function with arr and key to check for */
let isUnique = checkForUnique(arr,'name')

checkDuplicate(arr, item) {
const uniqueValues = new Set(arr.map((v) => v[item]));
return uniqueValues.size < arr.length;
},
console.log(this.checkDuplicate(this.dutyExemptionBase, 'CI_ExemptionType')); // true || false

It is quite interesting to work with arrays
You can use new Set() method to find duplicate values!
let's assume you have an array of objects like this...
let myArray = [
{ id: 0, name: "Jhon" },
{ id: 1, name: "sara" },
{ id: 2, name: "pop" },
{ id: 3, name: "sara" }
]
const findUnique = new Set(myArray.map(x => {
return x.name
}))
if(findUnique.size < myArray.length){
console.log("duplicates found!")
}else{
console.log("Done!")
}

const duplicateValues = [{ name: "abc" }, { name: "bcv" }, { name: "abc" }];
const isContainDuplicate = (params) => {
const removedDuplicate = new Set(params.map((el) => el.name));
return params.length !== removedDuplicate.size;
};
const isDuplicate = isContainDuplicate(duplicateValues);
console.log("isDuplicate");

Filter Array based on another array

I have a list with that contains a list of objects. Each object has 4 properties on it. There is a checkbox list with the unique values of two of the properties, this helps build my filter array.
the Filter might end up looking like this:
[
{
prop: 'username',
val: ['max', 'sam']
},
{
prop: 'color',
val: ['blue', 'green']
}
]
The list of objects would look something like this:
[
{
username: 'sam',
color: 'blue'
},
{
username: 'jimmy',
color: 'blue'
},
{
username: 'sam',
color: 'black'
},
{
username: 'max',
color: 'green'
},
{
username: 'max',
color: 'blue'
}
]
The Desired Result
[
{
username: 'sam',
color: 'blue'
},
{
username: 'max',
color: 'green'
},
{
username: 'max',
color: 'blue'
}
]
I feel like I'm going down a never ending forEach rabbit hole. I'm guessing I need some sort of recursion. Currently here is what I have:
var temporary = scope.transactions;
function getFilteredTransactions() {
var filter = deviceFilterService.get();
if (filter.length > 0) {
var temp2 = [];
angular.forEach(filter, function (fil) {
//object
angular.forEach(fil.val, function (filterValue) {
//list on each object
angular.forEach(temporary, function (transaction) {
if (transaction[fil.prop] === filterValue) {
if (temp2.indexOf(transaction) === -1) {
temp2.push(transaction);
}
}
});
temporary = temp2;
});
});
$log.debug(temporary);
scope.transactions = temporary;
} else {
initialize();
}
}
This is starting to work, the second time it goes through the property for color it ends up just wanting to add the exact same transaction to the temp2 array. There has to be a better way to set this up, possibly through recursion.

If you convert the format of the first list to a dictionary, i think if should get easier.
var dict = {};
angular.forEach(source1, function(ob){
dict[ob.prop] = ob.val;
});
function getFiltered(ob){
for(var prop in ob){
if(dict[prop] && dict[prop].indexOf(ob[prop]) === -1){
return false;
}
}
return true;
};
and just call it as:
var temporary = scope.transactions.filter(getFiltered);
Demo
Basically the first part converts:
[
{
prop: 'username',
val: ['max', 'sam']
},
{
prop: 'color',
val: ['blue', 'green']
}
];
to:
{
username:['max', 'sam'],
color:['blue', 'green']
}
so that it makes the look up much easier.

You might want to change the variable names here for clarity, but this will do what you're asking for:
var values = {};
angular.forEach(startingData, function(rawData) {
angular.forEach(rawData, function(value, key) {
if (angular.isUndefined(values[key])) {
values[key] = [];
}
if (values[key].indexOf(value) === -1) {
values[key].push(value);
}
})
});
var result = [];
angular.forEach(values, function(value, key) {
result.push({prop: key, val: value})
});

You can simply iterate each key of the data the needs filtering, find the appropriate filter per that key, and check the value against the filter values:
$scope.transactions = $scope.transactions.filter(isItemValidFilter);
function isItemValidFilter(item) {
var filters = deviceFilterService.get();
//For each property in the data, get the correct filter from the list of filters
var totalConditions = Object.keys(item).length;
var correctConditions = 0;
for (var filterKey in item) {
var correctFilters = filters.filter(function(dataFilter) {
return dataFilter.prop == filterKey
});
if (correctFilters.length) {
//Ill assume only 1 filter, so just use the 0 index
var correctFilter = correctFilters[0];
var conditions = correctFilter.val;
if (conditions && conditions.length) {
//check the values!
if (conditions.indexOf(item[filterKey]) > -1) {
correctConditions++;
}
}
}
}
return correctConditions === totalConditions;
}
Demo: http://jsfiddle.net/Lz32hka5/1/

Try:
var temp2 = [], matched;
angular.forEach(temporary, function(item){
matched = true;
angular.forEach(Object.keys(item), function(key){
angular.forEach(filter, function(filter){
filter.prop == key && filter.val.indexOf(item[key]) == -1 && (matched = false);
});
});
matched && temp2.push(item);
});
console.log(temp2)
temporary is the list of objects, filter: your filters
Demo: http://jsfiddle.net/wZVanG/7wnae850/

Get duplicate key names json jquery

I want an array which will fetch me duplicate keys of the json
Ex:
var catalog=[
{ ip: 'ipId_1', name: '192.160.121.11' },
{ ip: 'ipId_dyn_1_0', name: '192.160.121.12' },
{ ip: 'ipId_dyn_1_1', name: '192.160.121.12' }
];
Since 192.160.121.12 is repeating, i want an array like [ipId_dyn_1_0, ipId_dyn_1_1],
Tried so far (Fiddle Demo):
var categories =[];
var dup= [];
$.each(catalog, function(index, value) {
console.log( categories+''+value.name);
if ($.inArray(value.name, categories) == -1) {
categories.push(value.name);
}else{
dup.push(value.ip);
console.log(value.ip);
}
});
console.log(categories);
console.log(dup);

var cat_inverted = {}, categories = [];
$.each(catalog, function(index, value) {
if (cat_inverted[value.name]) {
cat_inverted[value.name].push(value.ip);
} else {
cat_inverted[value.name] = [value.ip];
categories.push(value.name);
}
});
var dup = [];
for (var name in cat_inverted) {
if (cat_inverted[name].length > 1) {
$.each(cat_inverted[name], function(i, ip) {
dup.push(ip);
});
}
}

Check:
var catalog=[
{ ip: 'ipId_1', name: '192.160.121.11' },
{ ip: 'ipId_dyn_1_0', name: '192.160.121.12' },
{ ip: 'ipId_dyn_1_1', name: '192.160.121.12' }
];
var my = {};
var dup = [];
$.each(catalog, function(index, value) {
if(!!!my[value.name]) {
my[value.name] = [];
}
my[value.name].push(value.ip);
});
$.each(my, function(index, value) {
if(value.length > 1) {
$.each(my[index], function(i, val) {
dup.push(val);
});
}
});
console.log(dup);
jsfiddle

If you use this:
var catalog=[
{ ip: 'ipId_1', name: '192.160.121.11' },
{ ip: 'ipId_dyn_1_0', name: '192.160.121.12' },
{ ip: 'ipId_dyn_1_1', name: '192.160.121.12' }
];
var values = {};
$.each(catalog, function(index, data) {
var name = data.name;
if(typeof values[name] == 'undefined') values[name] = [];
values[name].push(data.ip);
});
var dupes = [];
$.each(values,function(name,indexes) {
if(indexes.length > 1)
{
dupes.push(indexes);
}
});
console.dir(dupes);
dupes will now contain an array of arrays (sets of duplicates)
Give it a run and see how it works for ya

I would use lodash.js or underscore.js for this task because of the functional approach. You are more flexible in changing your task when using this approach.
You can store your data in an variable and later easily transform them to your desired data structure.
var catalog=[
{ ip: 'ipId_1', name: '192.160.121.11' },
{ ip: 'ipId_dyn_1_0', name: '192.160.121.12' },
{ ip: 'ipId_dyn_1_1', name: '192.160.121.12' }
];
var categoriesObjectsUniqe =[];
var categories =[];
var dupObjects= [];
var dup= [];
categoriesObjectsUniqe = _.unique(catalog, 'name');
categories = _.map(categoriesObjectsUniqe, function(val) {
return val.name; })
dupObjects = _.filter(catalog, function(current) {
return arr = _.filter(catalog, function(currentInner) {
return currentInner.name === current.name; }).length > 1;
});
dup = _.map(categoriesObjUniqe, function(val) {
return val.ip; })
console.log('uniqe Objects :');
console.log(categoriesObjectsUniqe);
console.log('uniqe IPs :');
console.log(categories);
console.log('duplicate Objects :');
console.log(dupObjects);
console.log('duplicate ips :');
console.log(dup);
Here is the fiddle for that.
http://jsfiddle.net/3wHfB/94/

Array selector function by property value

I have:
var array = [ { key: '1' }, { key: '2' }, { key: '3' } ]
I want:
var obj = getFirstItem(array, 'key', '2');
And as a result:
obj = { key: '2' }
Is there such function in JavsScript or jQuery?

I don't know of a built in function. However, it would be trivial to implement it yourself:
var data = [ { key: '1' }, { key: '2' }, { key: '3' } ];
function getFirstItem(input, key, value) {
for(var i = 0; i < input.length; i++) {
if(input[i][key] === value)
return input[i];
}
}
console.log(getFirstItem(data, "key", 2));

I don't think jQuery is really necessary here. The function is as simple as:
function getFirstItem(arr, k, v){
for(var i=0;i<arr.length;i++){
var obj = arr[i];
if(obj[k] == v)
return obj;
}
return null;
}
Live example: http://jsfiddle.net/QARAd/

Like others have said it's quite simple to just loop over the array yourself.
However there is a filter method in JS 1.5 (Apparently not supported in IE8 and lower, although the link has a compatibility work around)
var myarray = [ { key: '1' }, { key: '2' }, { key: '3' } ]
function getFirstItem(myarray, key) {
var result = myarray.filter(function(element, index, array) {
return element.key == key;
});
if (result.length)
return result[0];
return null;
}
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/filter
JSFiddle Example