Related
I need convert this object:
{
"en": "[\"En1\",\"En2\"]",
"de": "[\"De1\",\"De2\"]"
}
to:
[
{
"en": "En1",
"de": "De1"
},
{
"en": "En2",
"de": "De2"
}
]
Can you help me?
i tried as follows:
const obj = {
en: '["En1","En2"]',
de: '["De1","De2"]',
};
const result = Object.entries(obj).map(([key, value]) => ({
[key]: JSON.parse(value),
}));
console.log(result)
but this only returns me an array of objects and I don't know how to go ahead and create a new array with key-value matches.
const data = {
"en": "[\"En1\",\"En2\"]",
"de": "[\"De1\",\"De2\"]"
}
console.log(Object.values(Object.entries(data).reduce((a,[k,v])=>
(JSON.parse(v).forEach((e,i)=>(a[i]??={})[k]=e),a),{})))
You can separate your object into 2 arrays then combine them like this
const obj = {
en: '["En1","En2"]',
de: '["De1","De2"]',
};
// Convert to array, separate them by key
let en = JSON.parse(obj.en.split(','));
let de = JSON.parse(obj.de.split(','));
//then combine both arrays
const result = en.map((x,i) =>({
en:x,
de:de[i]
}))
console.log(result);
You can use a combination of Array#map and Array#reduce as follows. The number of items is not hard-corded, so this will work for any number of items:
const
input = { "en": "[\"En1\",\"En2\"]", "de": "[\"De1\",\"De2\"]"},
output = Object.entries(input)
.map(([key,vals]) => JSON.parse(vals).map(v => ({[key]:v})))
//..producing [[{"en":"En1"},{"en":"En2"}],.....]
.reduce(
(obj, values) =>
obj.length === 0 ?
values.map(v => v) : //initial result: [{"en":"En1"},{"en":"En2"}]
values.map((v,i) => ({...obj[i],...v})), //appends "de" prop to each element, ....
[]
);
console.log( output );
I've opted for a more imperative approach here. It appends objects to the returnArray array for each index of the parsed values array. If value matches idx + 1 (eg 'De1'.includes(1)), a key-value pair is initialized on the object at the current index of the returnArray array.
My answer relies on a lot of assumptions regarding the input. If the parsed string array elements are not in numerical order, or there are gaps in the values, eg De3, De1, De2, or De1, De6, the current solution doesn't account for it.
let returnArray = [];
Object.entries(obj).forEach(pair => {
let key = pair[0];
let values = JSON.parse(pair[1]);
values.forEach((_el, idx) => {
if (!returnArray[idx]) {
returnArray.push({});
}
let value = values[idx];
if (value.includes(idx + 1)) {
returnArray[idx][key] = values[idx];
}
});
});
So I have an array looks like this:
[
{ date: '2021-07-07' },
{ date: '2021-07-07' },
{ date: '2021-07-07' },
{ date: '2021-07-08' },
{ date: '2021-07-09' },
{ date: '2021-07-10' },
{ date: '2021-07-10' }
];
How can I split into 3 array (What I mean is 1 group for unique dates, and another group for duplicate, but if there more than 1 duplicate group, it should separate into another group)
It will looks like this after split
Array 1
[{"date": "2021-07-07"},{"date": "2021-07-07"},{"date": "2021-07-07"}]
Array 2
[{"date": "2021-07-08"},{"date": "2021-07-09"}]
Array 3
[{"date": "2021-07-10"},{"date": "2021-07-10"}]
Below is my code so far, but it only work if the duplicate on have 1
const findDuplicates = arr => {
let sorted_arr = arr.slice().sort();
let result = [];
for (let i = 0; i < sorted_arr.length - 1; i++) {
if (sorted_arr[i + 1].date == sorted_arr[i].date) {
result.push(sorted_arr[i]);
}
}
return result;
};
const filterSame = arr => {
let temp = findDuplicates(arr);
const result = arr.filter(date => date.date == temp[0].date);
return result;
};
const filterUnique = array => {
let result = array.filter(
(e, i) => array.findIndex(a => a['date'] === e['date']) === i
);
let temp = findDuplicates(array);
result = result.filter(function(obj) {
return obj.date !== temp[0].date;
});
return result;
};
You could create a map, keyed by dates, and with as value an empty array. Then populate those arrays. Finally extract the arrays that have more than one element, and add to that result a combined array of those single-element arrays:
function group(data) {
let map = new Map(data.map(o => [o.date, []]));
for (let o of data) map.get(o.date).push(o);
return [
...[...map.values()].filter(({length}) => length > 1),
[...map.values()].filter(({length}) => length == 1).flat()
];
}
let data = [{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-08"},{"date":"2021-07-09"},{"date":"2021-07-10"},{"date":"2021-07-10"}];
console.log(group(data));
Explanation
let map = new Map(data.map(o => [o.date, []]));
This creates a Map. The constructor is given an array of pairs. For the example data that array looks like this:
[
["2021-07-07", []],
["2021-07-07", []],
["2021-07-07", []],
["2021-07-08", []],
["2021-07-09", []],
["2021-07-10", []],
["2021-07-10", []]
]
The Map constructor will create the corresponding Map, which really removes duplicates. You can imagine it as follows (although it is not a plain object):
{
"2021-07-07": [],
"2021-07-08": [],
"2021-07-09": [],
"2021-07-10": []
}
Then the for loop will populate these (four) arrays, so that the Map will look like this:
{
"2021-07-07": [{date:"2021-07-07"},{date:"2021-07-07"},{date:"2021-07-07"}],
"2021-07-08": [{date:"2021-07-08"}],
"2021-07-09": [{date:"2021-07-09"}],
"2021-07-10": [{date:"2021-07-10"},{date:"2021-07-10"}]
}
In the return statement the Map values are converted to an array twice. Once to filter the entries that have more than 1 element:
[
[{date:"2021-07-07"},{date:"2021-07-07"},{date:"2021-07-07"}],
[{date:"2021-07-10"},{date:"2021-07-10"}]
]
...and a second time to get those that have 1 element:
[
[{date:"2021-07-08"}],
[{date:"2021-07-09"}],
]
The second array is flattened with flat():
[
{date:"2021-07-08"},
{date:"2021-07-09"},
]
The final result concatenates the first array (with duplicate dates) with the flattened array (with unique dates), using the spread syntax (...)
This could be done in a 2 step process
a typical group by operation based on the date properties
aggregating together all the groups which only have 1 result.
const input = [{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-08"},{"date":"2021-07-09"},{"date":"2021-07-10"},{"date":"2021-07-10"}]
const grouped = input.reduce ( (acc,i) => {
if(!acc[i.date]) acc[i.date] = []
acc[i.date].push(i);
return acc;
},{});
const final = Object.values(Object.entries(grouped).reduce( (acc,[key,values]) => {
if(values.length>1) {
acc[key] = values;
}
else{
if(!acc.others) acc.others = [];
acc.others.push(values[0]);
}
return acc
},{}))
console.log(final);
Note that if you added, for example, 2021-07-11 to your original array, this would get lumped in with all the other "unique" elements. This may or may not be what you expected, but was not clear from the question.
Another option is to sort the array before grouping. If the current date being looped isn't the same as its neighbors, then it doesn't have duplicates.
const input = [{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-07"},{"date":"2021-07-08"},{"date":"2021-07-09"},{"date":"2021-07-10"},{"date":"2021-07-10"}]
input.sort((a,b) => a.date.localeCompare(b.date))
const grouped = input.reduce((acc, o, i, arr) => {
const key = o.date === arr[i-1]?.date || o.date === arr[i+1]?.date
? o.date
: 'lonely'
acc[key] ||= []
acc[key].push(o);
return acc;
}, {});
console.log(Object.values(grouped));
I have a array of objects, for exemple:
let arr = [
{title:apple,quantity:2},
{title:banana,quantity:3},
{title:apple,quantity:5},
{title:banana,quantity:7}
];
array containe many same objects, and i want recived array with uniqe object :
let result = [
{title:apple,quantity:7},
{title:banana,quantity:10}
]
How can I do this?
You can iterate over your array and filter out all the object with same title. Then use reduce to add all the quantity and return a new object. Code is below,
let newArr = [];
arr.forEach((currentObj) => {
const alreadyExists = newArr.findIndex(item => currentObj.title === item.title) > -1;
if(!alreadyExists) {
const filtered = arr.filter(item => item.title === currentObj.title);
const newObject = filtered.reduce((acc, curr) => { return {...acc, quantity: acc.quantity += curr.quantity}}, {...currentObj, quantity: 0})
newArr.push(newObject);
}
})
console.log(newArr);
This is done on a phone so may have some typos but the gist is there:
const resultObj = arr.reduce((acc,curr) =>{
acc[curr.title] = acc[curr.title]== undefined? curr.quantity: acc[curr.title] + curr.quantity
return acc
},{})
const resultArr = Object.entries(resultObj).map([key,value]=>({title:key,quantity:value}))
You could do that in "one line" using arrow function expressions but it won't be very readable unless you know what's happening inside:
let arr = [
{title: "apple",quantity:2},
{title: "banana",quantity:3},
{title: "apple",quantity:5},
{title: "banana",quantity:7}
];
let newArr = [...arr.reduce((acc, {title, quantity}) =>
(acc.set(title, quantity + acc.get(title) || 0), acc), new Map())
].map(([title, quantity]) => ({title, quantity}));
console.log(newArr);
So basically the first part is the reduce method:
arr.reduce((acc, {title, quantity}) =>
(acc.set(title, quantity + acc.get(title) || 0), acc), new Map())
That will returns a Map object, where each title is a key (e.g. "apple") and the quantity is the value of the key.
At this point you have to convert the Map object into an array again, and you do it using the spread syntax.
After you got an array back, you will have it in the following form:
[["apple", 7], ["banana", 10]]
But that is not what you want yet, not in this form, so you have to convert it using the array's map method:
<array>.map(([title, quantity]) => ({title, quantity}))
To keep it concise it uses the destructuring assignment
Generate an array of objects in a format from an array of objects inside another array .
The Given array is :
let target =
[[{key: "subscriber_id", value: "1"},
{key: "msisdn_value", value: "2"}],
[{key: "subscriber_id", value: "3"},
{key: "msisdn_value", value: "4"}
]]
The expected array of objects should be :
result = [
{"subscriber_id":"1","msisdn_value":"2"},
{"subscriber_id":"3","msisdn_value":"4"},
]
Use nested map calls with Object.fromEntries and Object.values for a clean and concise solution like so:
const result = target.map(e => Object.fromEntries(e.map(Object.values)));
Or, for a more efficient solution, use reduce:
const result = target.map(e => e.reduce((a, { key, value }) => (a[key] = value, a), {}));
You can use map and destructuring
let target = [[{key: "subscriber_id",value: "1"},{key: "msisdn_value",value: "2"}],[{key: "subscriber_id",value: "3"},{key: "msisdn_value",value: "4"}]]
let final = target.map(data => {
let [{key:a,value:b},{key:c,value:d}] = data
return { [a]:b, [c]:d }
})
console.log(final)
Loop through each element if there are more than two elements in inner arrays
let target = [[{key: "subscriber_id",value: "1"},{key: "msisdn_value",value: "2"}],[{key: "subscriber_id",value: "3"},{key: "msisdn_value",value: "4"},{key: "key",value: "value"}]]
let final = target.map((data) => {
return data.reduce((obj,{key,value})=>{
obj[key] = value
return obj
},{})
})
console.log(final)
I have two object arrays. I want to merge with key with value
var a = [{"fit":["34","32","30","28"],"size":["x"]}]
var b = [{"size":["s","m","xl"],"fit":["36"]}]
Expected Output should be
Obj=[{"fit":["34","32","30","28","36"],"size":["x,"s","m","xl"]}]
My Code is
let arr3 = [];
b.forEach((itm, i) => {
arr3.push(Object.assign({}, itm, a[i]));
});
alert(JSON.stringify(arr3))
it gives [{"size":["x"],"fit":["34","32","30","28"]}] which wrong.
Use Array.reduce().
// Combine into single array (spread operator makes this nice)
const myArray = [...a, ...b];
// "reduce" values in array down to a single object
const reducedArray = myArray.reduce((acc, val) => {
return [{fit: [...acc.fit, ...val.fit], size: [...acc.size, ...val.size]}];
});
Edit: if you want the reducer to merge objects regardless of what keys and fields it has then you can do by iterating over the keys of the objects and merging them dynamically:
const reducedArray = myArray.reduce((acc, val) => {
const returnObject = {};
for (const eaKey in acc) {
returnObject[eaKey] = [...acc[eaKey], ...val[eaKey]];
}
return [returnObject];
});
If the fields of the objects aren't guaranteed keys then you will need to get even more dynamic in detecting the type of merge and how to do it, but it's possible and I will leave that as an exercise for you to figure out. :)
Note that if there are duplicate values in each of the "fit" and "size" arrays, they will not be deduplicated. You'd have to do that manually as a separate step either with extra logic in the reduce function or afterwards.
combine a and b in a single array then reduce it starting with an array having an object with empty fit and size arrays:
var a = [{ fit: ["34", "32", "30", "28"], size: ["x"] }];
var b = [{ size: ["s", "m", "xl"], fit: ["36"] }];
var obj = [...a, ...b].reduce(
(acc, curr) => {
Object.keys(curr).forEach(k => {
acc[0][k] = [...new Set([...(acc[0][k] || []), ...curr[k]])];
});
return acc;
},
[{}]
);
console.log(obj);
You can create a combine function that takes fit and size from any two objects and merges them.
Use it as a reducer to combine everything.
let combine = ({fit, size}, {fit: fit2, size: size2}) =>
({ fit: [...fit, ...fit2], size: [...size, ...size2] });
let result = [...a, ...b].reduce(combine);
Example:
var a = [{"fit":["34","32","30","28"],"size":["x"]}, {"fit": ["10", "11"], "size":["xxxxxxxxl"]}]
var b = [{"size":["s","m","xl"],"fit":["36"]}];
let combine = ({fit, size}, {fit: fit2, size: size2}) =>
({ fit: [...fit, ...fit2], size: [...size, ...size2] });
let result = [...a, ...b].reduce(combine);
console.log(result);
If you don't want to use the keys directly you could try
const arr3 = b.reduce((carry, current, index) => {
Object.keys(current)
.forEach(key => {
Object.assign(carry, { [key]: Array.prototype.concat.call(current[key], a[index][key])});
});
return carry;
}, {});