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How to create a sub-associative object from a list of array keys in JavaScript?

I have an object from user input. The keys to that object are separated by commas, and I just want to separate those keys and make the keys of the object.
The key_array below is dynamic from user input, generates a different array each time, below I give you an example.
I have shown the object in my code which you can see below. you can also see the output by running that code.
var main_array = {};
var key_array = {
'user,name' : 'user name',
'user,email' : 'Email address',
'order,id' : 123456,
'order,qty' : 2,
'order,total' : 300,
'order,product,0,name' : "product1",
'order,product,0,qty' : 1,
'order,product,0,price' : 100,
'order,product,1,name' : "product2",
'order,product,1,qty' : 1,
'order,product,1,price' : 200,
};
for (keys in key_array){
var value = key_array[keys];
// What do I do here to get the output I want?
main_array['[' + keys.split(",").join('][')+ ']'] = value;
}
console.log(main_array);
Running the code above will give you the following output which is incorrect. And the output I don't want.
{
[order][id]: 123456,
[order][product][0][name]: "product1",
[order][product][0][price]: 100,
[order][product][0][qty]: 1,
[order][product][1][name]: "product2",
[order][product][1][price]: 200,
[order][product][1][qty]: 1,
[order][qty]: 2,
[order][total]: 300,
[user][email]: "Email address",
[user][name]: "user name"
}
I want an output like JSON below, so please tell me how to do it.
{
"user":{
"email" : "Email address",
"name" : "user name"
},
"order":{
"id" : 123456,
"qty" : 2,
"total" : 300,
"product":[
{
"name" : "product1",
"price" : 100,
"qty" : 1
},{
"name" : "product2",
"price" : 200,
"qty" : 1
}
]
}
}
Note: Please do not use eval, as using eval in this way is terribly unreliable, bad work and unsafe. Because I get all my data from user input, the likelihood of abuse can increase.

Use Object.entries to go over key and values of object.
Split the key by , separator and then build the object.
While building object, make sure to merge the keys and values using mergeTo method.
Then convert the objects which has the numerical keys then convert to object using convertObjsToArray method.
var key_array = {
"user,name": "user name",
"user,email": "Email address",
"order,id": 123456,
"order,qty": 2,
"order,total": 300,
"order,product,0,name": "product1",
"order,product,0,qty": 1,
"order,product,0,price": 100,
"order,product,1,name": "product2",
"order,product,1,qty": 1,
"order,product,1,price": 200
};
const mergeTo = (target, obj) => {
Object.entries(obj).forEach(([key, value]) => {
if (typeof value === "object" && !Array.isArray(value)) {
if (!target[key]) {
target[key] = {};
}
mergeTo(target[key], obj[key]);
} else {
target[key] = value;
}
});
};
const convertObjsToArray = obj => {
Object.entries(obj).forEach(([key, value]) => {
if (typeof value === "object") {
if (Object.keys(value).every(num => Number.isInteger(Number(num)))) {
obj[key] = Object.values(value);
} else {
convertObjsToArray(obj[key]);
}
}
});
};
const res = {};
Object.entries(key_array).map(([key, value]) => {
const keys = key.split(",");
let curr = { [keys.pop()]: value };
while (keys.length > 0) {
curr = { [keys.pop()]: curr };
}
mergeTo(res, curr);
});
convertObjsToArray(res);
console.log(res);

You can create the objects and keys required from the string dynamically, take each key and split it to an array using split(','). Using each item in the array create the structure required. Assuming if a key is a number, then it's parent must be an array.
Object.keys(key_array).forEach(key => {
const path = key.split(',');
let current = main_array;
for (let i = 0; i < path.length - 1; i++) {
if (!current[path[i]]) {
current[path[i]] = path[i + 1] && !isNaN(path[i + 1]) ? [] : {};
}
current = current[path[i]];
}
current[path.pop()] = key_array[key];
});
console.log(main_array); // Desired result

How can I remove duplicates in an array of object?

I have an array which looks like this :
var array =
[
{
key : { id : 1 , pack : "pack 1"},
values : [
{
item : { id : 1 , name : "item1"},
itemP : {id : 2 , name : "itemP12"}
},
{
item : { id : 4 , name : "item4"},
itemP : {id : 2 , name : "itemP12"}
},
]
}
]
I want to remove duplicate itemP so with a function it will look like this :
var array =
[
{
key : { id : 1 , pack : "pack 1"},
values : [
{
item : { id : 1 , name : "item1"},
itemP : {id : 2 , name : "itemP12"}
},
{
item : { id : 4 , name : "item4"},
itemP : null
},
]
}
]
When I try I always have errors. It is possible to do this?
Update
I try to do this :
console.log(array.map(pack =>
pack.values.map((item) => {
var test = JSON.stringify(item)
var set = new Set(test)
return Array.from(set).map((item)=> JSON.parse(item))
}
)
))
Unexpected end of JSON input
I also try something will filter but it doesn't work:
console.log(this.package.map(pack => pack.values.filter(
(value, index , array) => array.itemP.indexOf(value) === index
)))

Instead of mapping every key property, I suggest cloning the whole structure and setting the object value as null in the cloned one, avoiding unintentionally mutating the original structure.
function nullifyDupes(array) {
const clone = JSON.parse(JSON.stringify(array));
const seen = {};
clone.forEach(pack => {
pack.values.forEach(items => {
for (const item in items) {
const id = items[item].id;
if (seen[id]) items[item] = null;
else seen[id] = true;
}
});
});
return clone;
}
const originalArray = [{
key : { id : 1 , pack : "pack 1"},
values : [{
item : { id : 1 , name : "item1"},
itemP : {id : 2 , name : "itemP12"}
},
{
item : { id : 4 , name : "item4"},
itemP : {id : 2 , name : "itemP12"}
}]
}];
const mutatedArray = nullifyDupes(originalArray);
console.log(mutatedArray);

To achieve expected result, use below option of using map
Loop array using map
Use nameArr to check duplicate and assigning null value
Loop values array and check the name in nameArr using indexOf and assign null
var array = [
{
key : { id : 1 , pack : "pack 1"},
values : [
{
item : { id : 1 , name : "item1"},
itemP : {id : 2 , name : "itemP12"}
},
{
item : { id : 4 , name : "item4"},
itemP : {id : 2 , name : "itemP12"}
}
]
}
]
console.log(array.map(v => {
let nameArr = []
v.values = v.values.map(val => {
if(nameArr.indexOf(val.itemP.name) !== -1){
val.itemP.name = null
}else{
nameArr.push(val.itemP.name)
}
return val
})
return v
}))

You can use map and an object to check if its already exist. Like
var obj = {}
and loop over values
var values = [
{
item : { id : 1 , name : "item1"},
itemP : {id : 2 , name : "itemP12"}
},
{
item : { id : 4 , name : "item4"},
itemP : {id : 2 , name : "itemP12"}
}
]
values.map((v) => {
if(!obj[v.itemP.id + '-' + v.itemP.name]) {
obj[v.itemP.id + '-' + v.itemP.name] = true;
return v;
}
return { item : v.item }
})

You can map your array elements to array objects which don't include your duplicates using .map(). For each iteration of .map() you can again use .map() for your inner values array to convert it into an array of objects such that the duplicates are converted to null. Here I have kept a seen object which keeps track of the properties seen and their stringified values. By looping over all the properties in your object (using for...of), you can work out whether or not the key-value pair has been seen before by using the seen object.
The advantage of this approach is that it doesn't just work with one property (ie not just itemP), but it will work with any other duplicating key-value pairs.
See example below:
const array = [{key:{id:1,pack:"pack 1"},values:[{item:{id:1,name:"item1"},itemP:{id:2,name:"itemP12"}},{item:{id:4,name:"item4"},itemP:{id:2,name:"itemP12"}}]}];
const seen = {};
const res = array.map(obj => {
obj.values = obj.values.map(vobj => {
for (let p in vobj) {
vobj[p] = seen[p] === JSON.stringify(vobj[p]) ? null : vobj[p];
seen[p] = seen[p] || JSON.stringify(vobj[p]);
}
return vobj;
});
return obj;
});
console.log(res);
For an approach which just removed itemP from all object in accross your array you can use:
const array = [{key:{id:1,pack:"pack 1"},values:[{item:{id:1,name:"item1"},itemP:{id:2,name:"itemP12"}},{item:{id:4,name:"item4"},itemP:{id:2,name:"itemP12"}}]}];
let itemP = "";
const res = array.map(obj => {
obj.values = obj.values.map(vobj => {
vobj.itemP = itemP ? null : vobj.itemP;
if('itemP' in vobj) {
itemP = itemP || JSON.stringify(vobj.itemP);
}
return vobj;
});
return obj;
});
console.log(res);

how to check object name?

I have object and this object include objects too. It looks like:
$scope.data = {
tree : {
name : 'oak',
old : 54
},
dog : {
name : 'Lucky',
old : 3
},
system1 : {
name : '',
old : ''
},
baby : {
name : 'Jack',
old : 1
},
cat : {
name : 'Fluffy',
old : 2
},
system2 : {
name : '-',
old : '-'
}
}
As you can see this objects has obj name like - tree, dog, system etc. And I want to take only objects with name system, but this name can changes like system1, system123, system8. So I try to use this reg exp for ignore numbers
replace(/\d+/g, '')
But I can't reach this object name. I try this:
angular.forEach($scope.data, function(item){conole.log(item)}) // but it shows content in obj not obj name..
How can I reach this obj name and distinguish this 2 system objects?

var data = {
tree : {
name : 'oak',
old : 54
},
dog : {
name : 'Lucky',
old : 3
},
system1 : {
name : '',
old : ''
},
baby : {
name : 'Jack',
old : 1
},
cat : {
name : 'Fluffy',
old : 2
},
system2 : {
name : '-',
old : '-'
}
}
data = Object.keys(data) // get keys
.filter(key => key.startsWith('system')) // filter keys starting with system
.map(key => data[key]) // map to the values, returning a new array
console.log(data) // and you have you array with systems

Pass another param to the function like key to the forEach callBack Function. It is the key of the each object inside the object in your use-case.
Check the below example
var items = {
car: {
a: 123
},
dog: {
b: 234
},
system: {
c: 456
}
};
angular.forEach(items, function(item, key) {
console.log(key);
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

You can use Object.keys(myObject), that return an array of all the keys of the passed object, for istance:
var myObject= {
cat : {
name : 'Fluffy',
old : 2
},
system2 : {
name : '-',
old : '-'
}
}
var keys = Object.keys(myObject); // Keys will be ['cat', 'system2']
Cheers

You have to pass another parameter to angular foreach function to get the key name of the object like this:-
angular.forEach($scope.data, function(item, key){ // Here key is the keyname of the object
console.log(item, key);
});

Check if name exists in object array

I have an object array that looks just about like this
var o = [
{
module : "mod1",
customUrl : [
{ "state" : "name1",
"options" : ["option1", "option2", "option3"]
},
{ "state" : "name2",
"options" : ["option1", "option2", "option3"]
}
]
},
{
module : "mod2",
customUrl : [
{ "state" : "name1",
"options" : ["option1", "option2", "option3"]
},
{ "state" : "name2",
"options" : ["option1", "option2", "option3"]
}
]
}
]
and in a function I a passed a string. I want to be able to check that string against the "module" keys and see if it matches any of them so like
checkName = function(name) {
//check if "name" matches any "module" in o
}
Is this possible (I am using underscore but normal javascript is fine too).Thanks!

You can use function some, like so
var checkName = function(name) {
return _.some(o, function (el) {
return el.module === name;
});
};
or some from Array
var checkName = function(name) {
return o.some(function (el) {
return el.module === name;
});
};
Example

Pure Javascript solution. This function returns false if the module name is not found or the position in the array when the name is found. This function does not count in duplicates, it only will give the position from the last match.
JSfiddle demo
var checkName = function(name) {
var flag=false;
for(var i=0; i<o.length;i++){
if(name === o[i].module){
flag=i;
}
}return flag;
};
console.log(checkName("mod2"));

Quite another way to do so wiit pure, native JavaScript: convert the object to string and check for exact module-part.
var checkName = function(haystack, needle) {
return JSON.stringify(haystack).contains('"module":"' + needle + '"')
}
checkName(o, 'mod1'); // returns true
checkName(o, 'mod4'); // returns false

Removing duplicate objects with Underscore for Javascript

I have this kind of array:
var foo = [ { "a" : "1" }, { "b" : "2" }, { "a" : "1" } ];
I'd like to filter it to have:
var bar = [ { "a" : "1" }, { "b" : "2" }];
I tried using _.uniq, but I guess because { "a" : "1" } is not equal to itself, it doesn't work. Is there any way to provide underscore uniq with an overriden equals function?

.uniq/.unique accepts a callback
var list = [{a:1,b:5},{a:1,c:5},{a:2},{a:3},{a:4},{a:3},{a:2}];
var uniqueList = _.uniq(list, function(item, key, a) {
return item.a;
});
// uniqueList = [Object {a=1, b=5}, Object {a=2}, Object {a=3}, Object {a=4}]
Notes:
Callback return value used for comparison
First comparison object with unique return value used as unique
underscorejs.org demonstrates no callback usage
lodash.com shows usage
Another example :
using the callback to extract car makes, colors from a list

If you're looking to remove duplicates based on an id you could do something like this:
var res = [
{id: 1, content: 'heeey'},
{id: 2, content: 'woah'},
{id: 1, content:'foo'},
{id: 1, content: 'heeey'},
];
var uniques = _.map(_.groupBy(res,function(doc){
return doc.id;
}),function(grouped){
return grouped[0];
});
//uniques
//[{id: 1, content: 'heeey'},{id: 2, content: 'woah'}]

Implementation of Shiplu's answer.
var foo = [ { "a" : "1" }, { "b" : "2" }, { "a" : "1" } ];
var x = _.uniq( _.collect( foo, function( x ){
return JSON.stringify( x );
}));
console.log( x ); // returns [ { "a" : "1" }, { "b" : "2" } ]

When I have an attribute id, this is my preffered way in underscore:
var x = [{i:2}, {i:2, x:42}, {i:4}, {i:3}];
_.chain(x).indexBy("i").values().value();
// > [{i:2, x:42}, {i:4}, {i:3}]

Using underscore unique lib following is working for me, I m making list unique on the based of _id then returning String value of _id:
var uniqueEntities = _.uniq(entities, function (item, key, a) {
return item._id.toString();
});

Here is a simple solution, which uses a deep object comparison to check for duplicates (without resorting to converting to JSON, which is inefficient and hacky)
var newArr = _.filter(oldArr, function (element, index) {
// tests if the element has a duplicate in the rest of the array
for(index += 1; index < oldArr.length; index += 1) {
if (_.isEqual(element, oldArr[index])) {
return false;
}
}
return true;
});
It filters out all elements if they have a duplicate later in the array - such that the last duplicate element is kept.
The testing for a duplicate uses _.isEqual which performs an optimised deep comparison between the two objects see the underscore isEqual documentation for more info.
edit: updated to use _.filter which is a cleaner approach

The lodash 4.6.1 docs have this as an example for object key equality:
_.uniqWith(objects, _.isEqual);
https://lodash.com/docs#uniqWith

Try iterator function
For example you can return first element
x = [['a',1],['b',2],['a',1]]
_.uniq(x,false,function(i){
return i[0] //'a','b'
})
=> [['a',1],['b',2]]

here's my solution (coffeescript) :
_.mixin
deepUniq: (coll) ->
result = []
remove_first_el_duplicates = (coll2) ->
rest = _.rest(coll2)
first = _.first(coll2)
result.push first
equalsFirst = (el) -> _.isEqual(el,first)
newColl = _.reject rest, equalsFirst
unless _.isEmpty newColl
remove_first_el_duplicates newColl
remove_first_el_duplicates(coll)
result
example:
_.deepUniq([ {a:1,b:12}, [ 2, 1, 2, 1 ], [ 1, 2, 1, 2 ],[ 2, 1, 2, 1 ], {a:1,b:12} ])
//=> [ { a: 1, b: 12 }, [ 2, 1, 2, 1 ], [ 1, 2, 1, 2 ] ]

with underscore i had to use String() in the iteratee function
function isUniq(item) {
return String(item.user);
}
var myUniqArray = _.uniq(myArray, isUniq);

I wanted to solve this simple solution in a straightforward way of writing, with a little bit of a pain of computational expenses... but isn't it a trivial solution with a minimum variable definition, is it?
function uniq(ArrayObjects){
var out = []
ArrayObjects.map(obj => {
if(_.every(out, outobj => !_.isEqual(obj, outobj))) out.push(obj)
})
return out
}

var foo = [ { "a" : "1" }, { "b" : "2" }, { "a" : "1" } ];
var bar = _.map(_.groupBy(foo, function (f) {
return JSON.stringify(f);
}), function (gr) {
return gr[0];
}
);
Lets break this down. First lets group the array items by their stringified value
var grouped = _.groupBy(foo, function (f) {
return JSON.stringify(f);
});
grouped looks like:
{
'{ "a" : "1" }' = [ { "a" : "1" } { "a" : "1" } ],
'{ "b" : "2" }' = [ { "b" : "2" } ]
}
Then lets grab the first element from each group
var bar = _.map(grouped, function(gr)
return gr[0];
});
bar looks like:
[ { "a" : "1" }, { "b" : "2" } ]
Put it all together:
var foo = [ { "a" : "1" }, { "b" : "2" }, { "a" : "1" } ];
var bar = _.map(_.groupBy(foo, function (f) {
return JSON.stringify(f);
}), function (gr) {
return gr[0];
}
);

You can do it in a shorthand as:
_.uniq(foo, 'a')