Change particular key in nested array to object in javascript

Change particular key in nested array to object in javascript - javascript

If the fields key in a object is array, change the first value of arrays as a key value pair object in javascript.
var obj =
[
{ id:1, fields:["item", "2", "list"]},
{ id:2, fields:["sample", "1", "check"]}
]
function newObj(obj) {
let objFields = {};
modifiedObj.fields.forEach(field => objFields[field] = field);
modifiedObj.fields= objFields;
return modifiedObj;
}
var result = this.newObject(obj)
Expected Output
{
item: "item",
sample: "sample"
}

Try this:
var obj =
[
{ id:1, fields:["item", "2", "list"]},
{ id:2, fields:["sample", "1", "check"]}
]
function newObject(obj) {
let objFields = {};
obj.forEach(e => {
if(e.fields && e.fields.length>0)
objFields[e.fields[0]] = e.fields[0];
});
return objFields;
}
var result = this.newObject(obj);
console.log(result);

Here is a functional approach that makes use of Object.assign(), spread operator, and Array.map() to create the object you need.
const input = [
{ id: 1, fields: ["item", "2", "list"] },
{ id: 2, fields: ["sample", "1", "check"] }
];
const process = (input) => (Object.assign(...input.map(({ fields }) => (
fields.length ? { [fields[0]]: fields[0] } : {}
))));
console.log(process(input));

Your snippet was close, you just needed to clean up the variable names, and then using map makes it a bit neater too:
const obj = [
{id: 1, fields: ["item", "2", "list"]},
{id: 2, fields: ["sample", "1", "check"]}
]
function newObj(inputArray) {
let outputObject = {};
inputArray.map(item => item.fields[0])
.forEach(field => outputObject[field] = field);
return outputObject;
}
var result = newObj(obj)
console.log(result)

Related

If object set has an object property create an array

I have a response value which is dynamic which i need to store in redux state,
Response consist of array of object and and name
ex :
{data:[
{name:"abc",age:"10",id:"10"}
{name:"abc",age:"15",id:"20"}
{name:"def",age:"15",id:"20"}
]
name: "abc"
}
So if the name is same I need to create array with the name.
Expected :
abc:[
{name:"abc",age:"10",id:"10"}
{name:"abc",age:"15",id:"20"}
]
something I tried
data.map(function(o) {
if(data.name ==o.name)
return name[o];
});

If you're wanting a new object with a key of the name property you could try something like this
const response = {
data: [{
name: "abc",
age: "10",
id: "10"
},
{
name: "abc",
age: "15",
id: "20"
},
{
name: "def",
age: "15",
id: "20"
},
],
name: "abc"
}
const createSet = (someData) => {
let key = someData.name
let data = someData.data.filter(e => e.name === key)
return {
[key]: data
}
}
console.log(createSet(response))

You can extract duplicated using reduce and filter :
var data = {
data:[
{name:"abc",age:"10",id:"10"},
{name:"abc",age:"15",id:"20"},
{name:"def",age:"15",id:"20"}
],
name: "abc"
}
const lookup = data.data.reduce((a, e) => {
a[e.name] = ++a[e.name] || 0;
return a;
}, {});
console.log(data.data.filter(e => lookup[e.name]));

JavaScript modify Array of Objects and alter contained data

I am having difficulties formatting some data. Currently, I receive data in the following structure.
[
{
"q1":"5",
"q2":[
"13",
"12",
],
"q3":"test",
}
]
I essentially need to modify this or even create a new object, that takes the following structure.
[
{
id: 1, //q1
answers: [
{
answer: '5',
},
],
},
{
id: 2, //q2
answers: [
{
answer: '13',
},
{
answer: '12',
},
],
},
{
id: 3, //q3
answers: [
{
answer: 'test',
},
],
},
];
So the id in the above would be obtained by remove the q and getting the number in the first data object. It would then have an answers array that would have an object for each answer.
I have been attempting this but have gotten lost. I don't know if I should use loops, mapping, filters etc. To be honest, the furthest I have got so far is obtaining the keys
var modified = data.map(function(item) {
return Object.keys(item)
})
I have created a JSFiddle where I have been attempting to do this.
Is there any way I can achieve the data I am after?
Many thanks

Please use map function.
const data = {
"q1":"5",
"q2":[
"13",
"12",
],
"q3":"test",
};
const result = Object.keys(data).map(key => {
let item = {id: key.substring(1), answers: []};
if(typeof data[key] === "string")
item.answers.push({answer: data[key]});
else
item.answers = data[key].map(val => ({answer: val}));
return item;
});
console.log(result)

const inputData = [
{
"q1":"5",
"q2":[
"13",
"12",
],
"q3":"test",
}
]
function answerMapper(objVal, id){
return Array.isArray(objVal)
?
{ id, answers: objVal.map(answer => ({ answer }))}
:
{ id, answers: [{answer: objVal }] }
}
function formatObject(obj){
return Object.keys(obj).map((k, i) => answerMapper(obj[k], i+1));
}
const result = inputData.map(obj => formatObject(obj));
// remove flatMap if your inputData has more than one entry
console.log(result.flatMap(x => x));

map over the first element of the data with Object.entries, grab the key and value, create a new answers array and return a new object.
const data = [{
"q1": "5",
"q2": [
"13",
"12",
],
"q3": "test",
}];
const out = Object.entries(data[0]).map(obj => {
const [ key, value ] = obj;
const id = Number(key[1]);
// If the the value is an array
// return a new array of mapped data
// Otherwise return an array containing
// one object
const answers = Array.isArray(value)
? value.map(el => ({ answer: el }))
: [{ answer: value }];
// Return the new object
return { id, answers };
});
console.log(out);

lets create a pure function which accepts the object in the array like so
const processObject = obj => Object.keys(obj).map(id => {
const answer = obj[id];
const answers = Array.isArray(answer) ? answer : [answer]
const answerObjectArray = answers.map(ans => ({
answer: ans
}));
return {
id: +id.substring(1),
answers: answerObjectArray
}
});
const dataArray = [{
"q1": "5",
"q2": [
"13",
"12",
],
"q3": "test",
}];
const output = processObject(dataArray[0]);
console.log(output);

Relate and merge array of same Department

I am working on an application where I need to get combine the object of same department based on the
conditions provided in the second Array and attach the relation to the object.
let inArr1 = [{"D1D2":"AND"},{"D3D4":"OR"}]
let inArr2 =[{"ID":"1","NAME":"KEN","DEPT1":"CSE"},
{"ID":"2","NAME":"MARK","DEPT2":"IT"},
{"ID":"3","NAME":"TOM","DEPT3":"ECE"},
{"ID":"4","NAME":"SHIV","DEPT4":"LIB"},
{"ID":"5","NAME":"TIM","DEPT5":"SEC"}
]
Output
outArr ={
[{"ID":"1","NAME":"KEN","DEPT1":"CSE","REL":"AND"},
{"ID":"2","NAME":"MARK","DEPT2":"IT","REL":"AND"}], //Arr1
[{"ID":"3","NAME":"TOM","DEPT3":"ECE","REL":"OR"},
{"ID":"4","NAME":"SHIV","DEPT4":"LIB","REL":"OR"}], //Arr2
[{"ID":"5","NAME":"TIM","DEPT5":"SEC"}] //Arr3
}
Code:
let condArr=[],outArr,i=1;
inArr1.forEach(condt => {
let dept = Object.keys(condt)[0];
let tmparr = dept.split("D");
tmparr.shift()
condArr.push(tmparr)
});
inArr2.forEach(condt => {
if(condArr.includes(inArr2.D+i)){
i++;
outArr.push(inArr2);
}
});

Your code has a bit confused logic, i would suggest rather this
let inArr1 = [{"D1D2":"AND"},{"D3D4":"OR"},{"D5D6":"AND"}]
let inArr2 =[{"ID":"1","NAME":"KEN","DEPT1":"CSE"},
{"ID":"2","NAME":"MARK","DEPT2":"IT"},
{"ID":"3","NAME":"TOM","DEPT3":"ECE"},
{"ID":"4","NAME":"SHIV","DEPT4":"LIB"},
{"ID":"5","NAME":"TIM","DEPT5":"SEC"},
{"ID":"6","NAME":"TLA","DEPT6":"SEC"},
]
// first lets create object of ids as keys and conditions as values
const [keys, conditions] = inArr1.reduce((agg, cond, index) => {
Object.entries(cond).forEach(([key, value]) => {
key.split('D').forEach(v => { if (v) agg[0][v] = { value, index }})
agg[1].push([])
})
return agg
}, [{}, []]) // {1: "AND", 2: "AND", 3: "OR", 4: "OR"}
conditions.push([])
// and now just map over all elements and add condition if we found id from the keys
inArr2.forEach(item => {
const cond = keys[item.ID]
if (cond) conditions[cond.index].push({...item, REL: cond.value})
else conditions[conditions.length - 1].push(item)
})
const res = conditions.filter(v => v.length)
console.log(res)

You could store the goups by using the ID and use new objects.
let inArr1 = [{ D1D2: "AND" }, { D3D4: "OR" }],
inArr2 = [{ ID: "1", NAME: "KEN", DEPT1: "CSE" }, { ID: "2", NAME: "MARK", DEPT2: "IT" }, { ID: "3", NAME: "TOM", DEPT3: "ECE" }, { ID: "4", NAME: "SHIV", DEPT4: "LIB" }, { ID: "5", NAME: "TIM", DEPT5: "SEC" }],
groups = inArr1.reduce((r, o) => {
Object.entries(o).forEach(([k, REL]) => {
var object = { REL, group: [] };
k.match(/[^D]+/g).forEach(id => r[id] = object);
});
return r;
}, {}),
grouped = inArr2.reduce((r, o) => {
var { REL, group } = groups[o.ID] || {};
if (group) {
if (!group.length) r.push(group);
group.push(Object.assign({}, o, { REL }));
} else {
r.push([o]);
}
return r;
}, []);
console.log(grouped);
.as-console-wrapper { max-height: 100% !important; top: 0; }

can try other solution:
let inArr1 = [{ D1D2: "AND" }, { D3D4: "OR" }, { D6D7: "XOR" }];
let inArr2 = [
{ ID: "1", NAME: "KEN", DEPT1: "CSE" },
{ ID: "2", NAME: "MARK", DEPT2: "IT" },
{ ID: "3", NAME: "TOM", DEPT3: "ECE" },
{ ID: "4", NAME: "SHIV", DEPT4: "LIB" },
{ ID: "5", NAME: "TIM", DEPT5: "SEC" },
{ ID: "9", NAME: "BAR", DEPT5: "XYZ" },
{ ID: "6", NAME: "FOO", DEPT5: "XYZ" },
];
let unmatchedArr = []
let matchedArr = inArr2.reduce((acc, obj) => {
// getting index matched from inArr1 objects key
const indexMatched = getIndexMatch(obj.ID);
// creating index if not exists
if (!acc[indexMatched] && indexMatched !== null) acc[indexMatched] = [];
// if some index matched it merge current obj with DEL property with inArr1[indexMatched] key => value
return indexMatched !== null
? acc[indexMatched].push({
...obj,
DEL: inArr1[indexMatched][Object.keys(inArr1[indexMatched])[0]]
})
// pushing on unmatchedArr
: unmatchedArr.push(obj)
, acc
}, []);
function getIndexMatch(id) {
for (const [index, obj] of inArr1.entries()) {
for (const key of Object.keys(obj)) {
// spliting only digits of the current key of object
if (key.match(/\d/g).includes(id)) return index; // returning index of inArr1 if is included
}
}
return null;
}
// merging arrays
const result = [...matchedArr, unmatchedArr];
console.log(result);

Deep merging nested arrays

I have to merge 2 arrays with key value as follows:
array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}]
with
array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}]
to produce something like
merged = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"},{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}]
I've been trying this out for quite some time and can't get a solution that meets the scenario. Most of the solutions just do blind merging, not based on the id value. Tried using lodash mergeWith but didn't get the output needed. A Ramda solution is also acceptable.
Thanks,

This links could be helpful to you merge two arrays.
In this code snippet, i have tried to find the common objects between set1 and set2,if there are any i'm finding the unique properties and changing their content and also non existant properties in object2 and pushing it to object1
Check the following snippet.
var arr1 = [{
id: "123",
data: [{
id: "234",
data: "hello"
}, {
id: "345",
data: "there"
}, {
id: "xyz",
data: "yo"
}]
}, {
id: "456",
data: [{
id: "34",
data: "test"
}, {
id: "45",
data: "test2"
}, {
id: "yz",
data: "test3"
}]
}, {
id: "789",
data: [{
id: "23",
data: "aaa"
}, {
id: "34",
data: "bbb"
}, {
id: "xy",
data: "ccc"
}]
}]
var arr2 = [{
id: "456",
data: [{
id: "45",
data: "changed"
}, {
id: "yz",
data: "data"
}]
}, {
id: "789",
data: [{
id: "456",
data: "appended data"
}]
}, {
id: "890",
data: [{
id: "456",
data: "new data"
}]
}]
var arr3 = [];
for (var i in arr1) {
var shared = false;
for (var j in arr2)
if (arr2[j].id == arr1[i].id) {
shared = true;
// arr1[i].data.concat(arr2[j].data);
var set1 = pushproperties(arr1[i].data, arr2[j].data);
arr1[i].data = set1;
arr3.push(arr1[i]);
break;
}
if (!shared) {
arr3.push(arr1[i]);
arr3.push(arr2[j]);
}
}
function pushproperties(set1, set2) {
var filtered = false;
set2.forEach(function(item) {
filtered = set1.every(function(element) {
return element.id != item.id;
});
if (filtered) {
set1.push(item);
}
});
set1.forEach(function(item) {
set2.forEach(function(element) {
if (item.id == element.id) {
item.data = element.data;
}
});
});
return set1;
}
console.log(arr3);
Hope this helps

This a function the merges 2 arrays recursively using Array.prototype.reduce(). If it encounters items with the same id, and they have a data prop, which is an array, it merges them using the logic. If data is not an array, it's overridden by the last item instead.
function mergeArraysDeep(arr1, arr2) {
var unique = arr1.concat(arr2).reduce(function(hash, item) {
var current = hash[item.id];
if(!current) {
hash[item.id] = item;
} else if (Array.isArray(current.data)) {
current.data = mergeArraysDeep(current.data, item.data);
} else {
current.data = item.data;
}
return hash;
}, {});
return Object.keys(unique).map(function(key) {
return unique[key];
});
}
var array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}
];
var array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}
];
var result = mergeArraysDeep(array1, array2)
console.log(result);
ES6 version that uses Map, Map.prototype.values(), and array spread:
const mergeArraysDeep = (arr1, arr2) => {
return [...arr1.concat(arr2).reduce((hash, item) => {
const current = hash.get(item.id);
if(!current) {
hash.set(item.id, item);
} else if (Array.isArray(current.data)) {
current.data = mergeArraysDeep(current.data, item.data);
} else {
current.data = item.data;
}
return hash;
}, new Map()).values()];
}
const array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}
];
const array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}
];
const result = mergeArraysDeep(array1, array2)
console.log(result);

Finally this is what worked for me. Thanks to #Geeky for showing the way:
function mergeArrays(arr1, arr2) {
var arr3, arrIdx = [];
if (!arr1 || arr1.length ==0) return arr2
for (var i in arr1) {
var shared = false;
for (var j in arr2)
if (arr2[j].id == arr1[i].id) {
shared = true;
joined = _.mergeWith({},arr1[i],arr2[j], function (a,b) {
if (_.isArray(a)) return b.concat(a)})
arr3.push(joined);
break;
}
if (!shared) {
arr3.push(arr1[i]);
}
}
for (var k in arr2) {
if (arrIdx[k] !=k) arr3.push(arr2[k])
}
return arr3
}

JSON - array of objects into objects of arrays

I have a series of JSON entries:
[{"num": "1","name_A": "Alex" ,"name_B": "Bob"}, {"num": "2","name_A": "Anne" ,"name_B": "Barbra"}]
I am trying to convert this array of Objects as painlessly as possible into two objects - one with title name_A, and the second with the title name_B. Objects have to contain the title and an array of matching num-name pairs:
[{title: "name_A", names:[{"1", "Alex}, {"2", "Anne"}]}, {title:"name_B", names: [{"1", "Bob"}, {"2", "Barbra"}]}]
At first I tried simply to create two objects by reducing the array of object twice, once for name_A and second time for name_B and later glue everything together:
// get 'names' array
var name_A = objArray.reduce(function(memo, curr) {
memo.push({curr.num, curr.name_A})
return memo;
}, []);
But even this is failing. Why there is no push method for memo if I initialize reduce with an empty array?
And second question, am I on a right track or is there a better way to achieve this?

Comments inline, made a few minor corrections to the expectations.
var input = [{ "num": "1", "name_A": "Alex", "name_B": "Bob" }, { "num": "2", "name_A": "Anne", "name_B": "Barbra" }]
var output = input.reduce(function (a, b) {
// construct new objects and set their properties
var i = {};
i[b.num] = b.name_A;
var j = {};
j[b.num] = b.name_B;
// add them to our collection elements
a[0].names.push(i);
a[1].names.push(j);
return a;
// initializing our collection
}, [{ title: "name_A", names: [] }, { title: "name_B", names: [] }]);
// pretty print our output
console.log(JSON.stringify(output, null, " "))
var input = [{ "num": "1", "name_A": "Alex", "name_B": "Bob" }, { "num": "2", "name_A": "Anne", "name_B": "Barbra" }]
var output = input.reduce(function (a, b) {
// construct new objects and set their properties
var i = {};
i[b.num] = b.name_A;
var j = {};
j[b.num] = b.name_B;
// add them to our collection elements
a[0].names.push(i);
a[1].names.push(j);
return a;
// initializing our collection
}, [{ title: "name_A", names: [] }, { title: "name_B", names: [] }]);
so.log(output)
<pre id="output"></pre>
<script>
var so = {
log: function(o) {
document.getElementById("output").innerHTML = JSON.stringify(o, null, " ")
}
}
</script>

The problem with your code is that { curr.num, curr.name_A } is not a valid object, it's missing the property names. I've added properties num and name in my code below.
var name_A = [];
var name_B = [];
objArray.forEach(function(curr) {
name_A.push({num: curr.num, name: curr.name_a});
name_B.push({num: curr.num, name: curr.name_B});
});
var result = [
{ title: "name_A" }, names: name_A },
( title: "name_B" }, names: name_B }
];
Also, if you want to make an array out of the results of looping over an array, you should use .map rather than .reduce.

Assuming only property num is fixed. All other properties are treated as data, like name_A or name_B.
var a = [{ "num": "1", "name_A": "Alex", "name_B": "Bob" }, { "num": "2", "name_A": "Anne", "name_B": "Barbra" }],
result = [];
a.forEach(function (el) {
var num = el.num;
Object.keys(el).forEach(function (k) {
function tryFindIndexAndSetNames(aa, i) {
if (aa.title === k) {
result[i].names[num] = el[k];
return true;
}
}
if (k !== 'num' && !result.some(tryFindIndexAndSetNames)) {
var o = {};
o[num] = el[k];
result.push({ title: k, names: o });
}
});
});
document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');

Develop Reference

JavaScript is the programming language of the Web.

Change particular key in nested array to object in javascript - javascript

Related

If object set has an object property create an array

JavaScript modify Array of Objects and alter contained data

Relate and merge array of same Department

Deep merging nested arrays

JSON - array of objects into objects of arrays

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