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how to convert an object to array of objects

I have data in the following format
const data =
{
"sent_total":429,
"sent_distribution":[
{
"date_triggered__date":"2022-12-07",
"count":92
},
{
"date_triggered__date":"2022-12-08",
"count":337
}
],
"delivered":428,
"delivered_distribution":[
{
"timestamp__date":"2022-12-07",
"count":91
},
{
"timestamp__date":"2022-12-08",
"count":337
}
],
}
Need help in converting this in the following format which separates the data by the key (which is sent or delivered) to an array of objects.
const data = [
{
key: sent,
value: 429,
distribution: [
{
date_triggered__date: "2022-12-07",
count: 92,
},
{
date_triggered__date: "2022-12-08",
count: 337,
},
],
},
];

Hope it helps:
const data =
{
"sent_total":429,
"sent_distribution":[
{
"date_triggered__date":"2022-12-07",
"count":92
},
{
"date_triggered__date":"2022-12-08",
"count":337
}
],
"delivered":428,
"delivered_distribution":[
{
"timestamp__date":"2022-12-07",
"count":91
},
{
"timestamp__date":"2022-12-08",
"count":337
}
],
}
const result = [];
Object.keys(data).map((key) => {
const newKey = key.split("_")[0];
let index = result.findIndex((resultItem) => resultItem.key === newKey);
const value = key.includes("_distribution") ? null : data[key];
const distribution = key.includes("_distribution") ? data[key] : null;
if(index === -1) {
result.push({
key: newKey,
value: value,
distribution: distribution
});
} else {
if(value)
result[index].value = value;
if(distribution)
result[index].distribution = distribution;
}
});
console.log(result);

Using array, How to print name of students who has highest marks in Javascript?

The code i tried
function findHighest(){
var highest = 0; // assum min 0
var highestItem;
$('tr').each(function(index, item){
if(index > 0){
var math = $(item).find('td').eq(1).text();
var eng = $(item).find('td').eq(2).text();
var lit = $(item).find('td').eq(3).text();
//alert(math)
var sum = parseFloat(math) + parseFloat(eng) + parseFloat(lit)
if (sum > highest){
highest = sum;
highestItem = item;
}
}
})
$(highestItem).css({ 'font-style': 'italic', 'color': 'red' });
}
I am trying to find name of student who got highest marks in class in at least two subjects in JavaScript?

const highestMarks=[];
const studentsWithHighestMarks=[];
const students = [{ name: "mini", subject: [{ maths : 20}, {english: 23}, { science: 25}, { sports: 24}] }, { name: "jerry", subject: [{ maths : 22}, {english: 20}, { science: 20}, { sports: 21}] }, { name: "john", subject: [{ maths : 23}, {english: 25}, { science: 20}, { sports: 21}] }];
students.forEach(student=>{
student.subject.forEach(subject=>{
for(let key in subject){
var index = highestMarks.findIndex(obj => {
return obj.subject === key
});
if (index===-1) {
highestMarks.push({
subject:key,
marks:subject[key],
students:[student.name]
})
}else if(highestMarks[index].marks<subject[key]){
highestMarks[index].marks=subject[key];
highestMarks[index].students=[student.name];
}
else if(highestMarks[index].marks==subject[key]){
highestMarks[index].marks=subject[key];
highestMarks[index].students.push(student.name);
}
}
})
});
students.forEach(student=>{
let count=0;
highestMarks.forEach(item=>{
if(item.students.includes(student.name)){
count++;
}
});
if(count>=2){
studentsWithHighestMarks.push(student.name)
}
})
console.log(studentsWithHighestMarks)

const subjectsConsidering = 2;
const getStudentMarks = (student) => {
const studentMarksList = [];
student.subject.forEach((subjectData) => {
studentMarksList.push(Object.values(subjectData)[0]);
});
const sum = studentMarksList.sort().reverse().reduce((sum, a, index) => {
// restrict only for first 2 subjects
if (index < subjectsConsidering) {
return sum + a;
}
return sum + 0;
});
return sum;
}
students.sort((studentA, studentB) => {
//return 0 for equal marks
return getStudentMarks(studentA) > getStudentMarks(studentB) ? -1 : 1;
});
console.log(students);
//This gives the sorted array of students having the highest marks in at least 2 subjects.

// Transform the data into a more manageable format
// { "subject": [["name", grade], ["name", grade], ["name", grade]] }
let transformed = students.reduce(
(data, student) => {
student.subject.forEach(subject => {
const key = keys(subject)[0];
const grade = [student.name, subject[key]];
if (!(key in data)) {
data[key] = [];
}
data[key].push(grade);
})
return data;
},
{}
)
// Utility function to compare grades
function gradeCompare(a, b) {
return a[1] > b[1] ? -1 : 1;
}
// List the top student in each subject
let names = Object.keys(transformed).map((subject) => {
return transformed[subject].sort(gradeCompare)[0][0];
});
// names :: [ "john", "john", "mini", "mini" ]
// Count the student names
let counts = names.reduce((acc, current) => {
acc[current] = (acc[current] || 0) + 1;
return acc;
}, {});
// counts :: { john: 2, mini: 2 }
// Find the maximum occurring count
let maxCount = Math.max(...Object.values(counts));
// maxCount :: 2
// Filter the keys that have that count
let topStudents = Object.keys(counts).filter(k => counts[k] === maxCount);
// topStudents :: [ "john", "mini" ]

Cant access data inside nested array of objects

I have an array of objects that I want to iterate over and create a new array of objects.
First I map over the data, then I loop through each object to extract the values. I want to store the Location name and value from each object.
My code is returning null results. I can't change the way data is declared. Can someone help me understand why I keep getting null results?
[
{
"euValue": null,
"asValue": null
}
]
const data = [{
Locations: [{
Location: {
Name: "Europe"
},
Value: "Ireland"
},
{
Location: {
Name: "Asia"
},
Value: "China"
}
]
}];
const formatData = () => {
let formattedData = [];
let euValue, asValue;
formattedData = data.map(location => {
for (const l in location) {
if (location.hasOwnProperty(l)) {
const _this = location[l];
euValue = _this.Location === "Europe" ? _this.Value : null;
asValue = _this.Location === "Asia" ? _this.Value : null;
}
}
return {
euValue,
asValue
};
});
return formattedData;
};
const newData = formatData();
console.log(newData);
Edit
Expected result is
[
{
"euValue": “Ireland”,
"asValue": “China”
}
]

Assuming that inside data you could have multiple objects with a Location array that have only 2 objects (one for Europe and another one for Asia) you should change your function to something like this
const data = [
{
Locations: [
{
Location: { Name: "Europe" },
Value: "Ireland"
},
{
Location: { Name: "Asia" },
Value: "China"
}
]
}
];
const formatData = () => {
// iterate all data objects
return data.map((topLocation) => {
const res = {};
// loop over Location children objects
topLocation.Locations.forEach((location) => {
const { Name } = location.Location;
// decide where to save Value base on the Location.name
if (Name === "Europe") {
res.euValue = location.Value;
} else if (Name === "Asia") {
res.asValue = location.Value;
}
});
return res;
});
};
const newData = formatData();
console.log(newData);

you missing a second loop also you overwriting the usValue and euValue and you better use forEach instead of map in this case.
const data = [{
Locations: [{
Location: {
Name: "Europe"
},
Value: "Ireland"
},
{
Location: {
Name: "Asia"
},
Value: "China"
}
]
}];
const formatData = (data) => {
let formattedData = [],
values = {};
data.forEach(location => {
for (const l in location) {
if (location.hasOwnProperty(l)) {
const _this = location[l];
_this.forEach(el => {
if (el.Location.Name === "Europe") {
values["euValue"] = el.Value || null
}
if (el.Location.Name === "Asia") {
values["asValue"] = el.Value || null
}
})
}
}
});
formattedData.push(values)
return formattedData;
};
console.log(formatData(data))

I don't know what do you want to get from your code but this code may help you.
const data = [{
Locations: [{
Location: {
Name: "Europe"
},
Value: "Ireland"
},
{
Location: {
Name: "Asia"
},
Value: "China"
}
]
}];
const formatData = () => {
let formattedData = [];
formattedData = data.map(location => {
let euValue = [],
asValue = [];
for (const l in location.Locations) {
if (location.Locations.hasOwnProperty(l)) {
const _this = location.Locations[l];
if (_this.Location.Name === "Europe")
euValue.push(_this.Value);
else if (_this.Location.Name === "Asia")
asValue.push(_this.Value);
}
}
return {
euValue,
asValue
};
});
return formattedData;
};
const newData = formatData();
console.log(newData);

I'm sure many of the other answers are fine but the way I did it was to do the classic for loop to iterate over the data. I would have liked to have kept your ternary operators but I think you may need the if/else syntax.
var data = [{
Locations: [{
Location: {
Name: "Europe"
},
Value: "Ireland"
},
{
Location: {
Name: "Asia"
},
Value: "China"
}
]
}];
const formatData = () => {
let formattedData = [];
let euValue, asValue;
formattedData = data.map(location => {
for (const l in location) {
if (location.hasOwnProperty(l)) {
const _this = location[l];
for (let i = 0; i < _this.length; i++) {
if (_this[i].Location.Name === "Europe") {
euValue = _this[i].Value;
} else if (_this[i].Location.Name === "Asia") {
asValue = _this[i].Value;
} else {
euValue, asValue = null;
}
}
}
}
return {
euValue,
asValue
};
});
return formattedData;
};
const newData = formatData();
console.log(newData);

Using Array.prototype.flatMap() might help you get the array you desire in a cleaner way:
const data = [{
Locations: [{
Location: {
Name: "Europe"
},
Value: "Ireland"
},
{
Location: {
Name: "Asia"
},
Value: "China"
}
]
}];
const formatData = () => {
const formattedData = data.flatMap(item => {
const object = {}
item.Locations.map(location => {
const continent = location.Location.Name
let country = {}
if (continent === 'Europe') country = {
euValue: location.Value
}
if (continent === 'Asia') country = {
asValue: location.Value
}
Object.assign(object, country)
});
return object
});
return formattedData;
}
const newData = formatData();
console.log(newData);

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/