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Conversion of array of object to object

I have an array of objects:
const action_triggers = [
{
onClick: {
action_id: "1",
},
},
{
onLoad: {
action_id: "2",
},
},
];
How do I convert it into the following by JavaScript?
const action_trigger = {
onClick: {
action_id: 1
},
onLoad: {
action_id: 2
}
}

Here is the reduce version
const _l = (s) => {
console.log(s);
};
let flatter = action_triggers.reduce((propogator, prop) => {
for (const [key, value] of Object.entries(prop)) {
propogator[key] = value;
}
return propogator;
}, {});
_l(flatter);
Helps with conditionally doing whatever you want to {} the input

How to check if a value in an array is present in other object and accordingly return a new object

I have an array
const dataCheck = ["Rohit","Ravi"];
I have another array of object
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
I want to check if any value in dataCheck is present in the userData and then return a new array with the below data
const newData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit", status: "present" },
{ name: "Ravi", status: "present" },
];
I tried to do something using loops but not getting the expected results
const dataCheck = ["Rohit", "Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" }
];
let newDataValue = {};
let newData = [];
userData.forEach((user) => {
const name = user.name;
dataCheck.forEach((userName) => {
if (name === userName) {
newDataValue = {
name: name,
status: "present"
};
} else {
newDataValue = {
name: name
};
}
newData.push(newDataValue);
});
});
console.log(newData);
My trial gives me repeated results multiple results which is just duplicates

You should use map() and a Set.
const dataCheck = ["Rohit","Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
const set = new Set(dataCheck);
const output = userData.map(data => set.has(data.name) ? ({...data, status: "present"}): data)
console.log(output)
.as-console-wrapper { max-height: 100% !important; top: 0; }
A Set allows for lookups in O(1) time and therefore this algorithm works in O(n) time. If you would use the array for lookups (e.g. using indcludes(), find() etc.) the runtime would be O(n²). Although this will certainly not matter at all for such small arrays, it will become more relevant the larger the array gets.
map() is used here because you want a 1:1 mapping of inputs to outputs. The only thing to determine then is, what the output should be. It is either the input, if the value is not in the Set, or it is the input extended by one property status set to "present". You can check for the presence in a Set using the has() method and can use the ternary operator ? to make the decision which case it is.

const dataCheck = ["Rohit", "Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
// map through every object and check if name property
// exists in data check with help of filter.
// if it exists the length of filter should be 1 so
// you should return { name: el.name, status: "present" } else
// return { name: el.name }
let newData = userData.map((el) => {
if (dataCheck.filter((name) => name === el.name).length > 0) {
return { name: el.name, status: "present" };
} else {
return { name: el.name };
}
});
console.log("newdata: ", newData);

A better approach would be to use map over userData array, find for matching element in dataCheck, if found return matching element + a status key or just return the found element as it is.
const dataCheck = ["Rohit","Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
const getUpdatedObject = () => {
return userData.map(userData => {
const userDetail = dataCheck.find(data => userData.name === data);
if(userDetail) return {userDetail, status:"present"}
else return {...userData}
});
}
console.log(getUpdatedObject())
Working fiddle

Loop through userData, check if name is includes in dataCheck. If true add status 'present'.
const dataCheck = ["Rohit","Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
for (let user of userData) {
if(dataCheck.includes(user.name)) {
user.status = 'present'
}
}
console.log(userData)

You are seeing repeated results due to the second loop dataCheck.forEach((userName) => { as every loop of dataCheck will fire the if/else statement and add something to the final array. However many values you add to dataCheck will be however many duplicates you get.
Only need to loop through one array and check if the value is in the other array so no duplicates get added.
const dataCheck = ["Rohit", "Ravi"];
const userData = [{ name: "Sagar" }, { name: "Vishal" }, { name: "Rohit" }, { name: "Ravi" }];
let newDataValue = {};
let newData = [];
// loop thru the users
userData.forEach((user) => {
// set the user
const name = user.name;
// check if in array
if (dataCheck.indexOf(name) >= 0) {
newDataValue = {
name: name,
status: "present",
};
}
// not in array
else {
newDataValue = {
name: name,
};
}
newData.push(newDataValue);
});
console.log(newData);

So you will do like this :
const dataCheck = ["Rohit","Ravi"];
const userData = [
{ name: "Sagar" },
{ name: "Vishal" },
{ name: "Rohit" },
{ name: "Ravi" },
];
const newUserData = userData.map( user => {
dataCheck.forEach( data => {
if( data === user.name )
user.status = "present";
});
return user;
} );
console.log( newUserData );

Modifying a specific value in a nested object (JavaScript)

I got this type of object:
const obj = {
group: {
data: {
data: [
{
id: null,
value: 'someValue',
data: 'someData'
}
]
}
}
};
I need to edit this object so whenever null is in the property value,
it would be replaced with some string.
Meaning if the replacement string will be 'someId',
the expected outcome is:
const obj = {
group: {
data: {
data: [
{
id: 'someId',
value: 'someValue',
data: 'someData'
}
]
}
}
};
Closest I found were this and this but didn't manage to manipulate the solutions there to what i need.
How should I do it?

Probably running into issues with the array values. Pass in the index of the array to modify. In this case [0]
obj.group.data.data[0].id = "someId"
EDIT
This will update all null values of id inside the data array:
obj.group.data.data.forEach(o => {
if (o.id === null) {
o.id = "someId"
}
})
Another EDIT
Here is an algorithm to recursively check all deeply nested values in an object. It will compile an array of object paths where null values live. There is an included helper method to find and update the value of the object at the given path in the array. There is a demonstration of the program in the console.
const object = {
group: {
data: {
data: [
{
id: null,
value: "foo",
data: [null, "bar", [null, { stuff: null }]]
},
{
id: null,
value: null,
data: {
bar: [null]
}
},
{
id: null,
value: "foo",
data: null
},
{
id: 4,
value: "foo",
data: "bar"
},
{
id: 4,
value: "stuff",
data: null
}
]
},
attributes: null,
errors: ["stuff", null]
}
}
const inspectProperty = (key, obj, path = "") => {
if (typeof obj[key] === "object") {
if (obj[key] instanceof Array) {
return analyzeArray(obj[key], `${path ? path + "." : ""}${key}`);
}
return analyzeObj(obj[key], `${path ? path + "." : ""}${key}`);
}
return [];
};
const analyzeKey = (obj, key, path = "") => {
if (obj[key] === null) return [`${path ? path + "." : ""}${key}`];
return inspectProperty(key, obj, path).reduce((a, k) => [...a, ...k], []);
};
const analyzeObj = (obj, path = "") => {
return Object.keys(obj).map((item) => analyzeKey(obj, item, path));
};
const analyzeArray = (array, path) => {
return array.map((item, i) => analyzeKey(array, i, path));
};
const updateNullValue = (path, value) => {
let p = path.split(".");
p.reduce((accum, iter, i) => {
if (i === p.length - 1) {
accum[iter] = value;
return object;
}
return accum[iter];
}, object);
};
let nullValues = analyzeObj(object)[0]
console.log(nullValues)
nullValues.forEach((nullVal, i) => {
updateNullValue(nullVal, "hello-" + i)
})
console.log(object)

Find element in map

I have a map of objects:
"0": {
key: 'id',
value: {
name: "eval"
// other variables
}
},
"1": {
key: 'id',
value: {
name: "help"
// other variables
}
} // and so on
I need to find an element in map that's name variable is eqaul to "eval". What's the easiest way to do this?

If "map" is an array
let arr = [{key:'id', value:{ name:'eval' }}]
let item = arr.find(el => el.value.name == 'eval')
If "map" is an object
let obj = {0:{key:'id', value:{ name:'eval' }}}
let item = Object.values(obj).find(el => el.value.name == 'eval')

Use <Array>.from to convert map values to array and after filter what you want.
const map = new Map();
map.set(0, {
key: 'id',
value: {
name: "eval"
}
});
map.set(1, {
key: 'id',
value: {
name: "help"
}
});
const result = Array.from(map.values())
.filter(x => x.value.name === 'eval')[0];
console.log(result);

The good old forEach Loop can do it too.
const data = [{
key: 'id',
value: {
name: "eval"
// other variables
}
},
{
key: 'id',
value: {
name: "help"
// other variables
}
}]
let res = [];
data.forEach((el) => {
if (el.value.name === "eval") {
res.push(el);
}
})
console.log(res)

You can do this
const tmp = {
"0": {
key: "id",
value: {
name: "eval"
// other variables
}
},
"1": {
key: "id",
value: {
name: "eval"
// other variables
}
}
};
function findEval(obj, target) {
const elem = Object.keys(obj).filter(key => tmp[key].value.name === target);
return elem.map(e => obj[e]);
}
console.log(findEval(tmp, 'eval'))
but better use lodash Find property by name in a deep object

simple and best solution
const tmp = {
"0": {
key: "id",
value: {
name: "eval"
// other variables
}
},
"1": {
key: "id",
value: {
name: "eval"
// other variables
}
}
};
function findEval(obj, target) {
for (var i=0; i < Object.keys(obj).length; i++) {
if (obj[i].value.name === target) {
return obj[i].value.name;
}
}
}
console.log(findEval(tmp, 'eval'))

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);