I have an array like this:
var clients=[{"id":1,"name":"john","age":20},
{"id":3,"name":"dean","age":23},
{"id":12,"name":"harry","age":14},
{"id":1,"name":"sam","age":22},
{"id":13,"name":"Bolivia","age":16},
{"id":7,"name":"sabi","age":60},
{"id":7,"name":"sahra","age":40},
{"id":4,"name":"natie","age":53},{"id":7,"name":"many","age":22}]
I want to find the duplicate objects and cluster them like this:
[
{
"id":1,
"clients":[
{"id":1,"name":"john","age":20},
{"id":1,"name":"sam","age":22}
]
},
{
"id":7,
"clients":[
{"id":7,"name":"sabi","age":60},
{"id":7,"name":"sahra","age":40},
{"id":7,"name":"many","age":22}
]
}
]
can I do that with filter() like this:clients.reduce(//code hier)?
reduce() is tailor made for this. When you want to aggregate over an array and get a computed result, you should use reduce().
find() is another array method, which helps in finding an array element based on a condition (here the matching of id property).
var clients=[{"id":1,"name":"john","age":20},
{"id":3,"name":"dean","age":23},
{"id":12,"name":"harry","age":14},
{"id":1,"name":"sam","age":22},
{"id":13,"name":"Bolivia","age":16},
{"id":7,"name":"sabi","age":60},
{"id":7,"name":"sahra","age":40},
{"id":4,"name":"natie","age":53},{"id":7,"name":"many","age":22}]
let ans = clients.reduce((agg,x,index) => {
let findI = agg.find( a =>
a.id === x.id
);
if(findI) findI.clients.push(x);
else {
agg.push({
id : x.id,
clients : [x]
});
}
return agg;
},[]);
console.log(ans);
The simplest solution would be to loop over the clients and check for an existing object with the same id. If yes, push to clients array. Or else, just create one.
var clients = [{ "id": 1, "name": "john", "age": 20 },
{ "id": 3, "name": "dean", "age": 23 },
{ "id": 12, "name": "harry", "age": 14 },
{ "id": 1, "name": "sam", "age": 22 },
{ "id": 13, "name": "olivia", "age": 16 },
{ "id": 7, "name": "sabi", "age": 60 },
{ "id": 7, "name": "sahra", "age": 40 },
{ "id": 4, "name": "natie", "age": 53 }, { "id": 7, "name": "kany", "age": 22 }]
const groups = [];
for (let client of clients) {
const existingGroup = groups.find(group => group.id == client.id)
if (existingGroup)
existingGroup.clients.push(client);
else {
groups.push({ id: client.id, clients: [client] });
}
}
console.log(groups);
You can reassign the original object with the temporary object just used for this, and continue with your business logic, which I believe is the one you are looking for.
Related
I'm using knockoutjs, but the question is really in Javascript domain.
I have variable vm.filteredSerivces() which contains all services by all employees.
Now, I want to just preserve those filteredSerivces where is vm.filteredSerivces()[0].GroupedServices[x].EmployeeId == 3684 (x is the number of index number of each object in GroupedServices object list)
I tried as follows:
var filteredSrvcs = vm.filteredSerivces()[0].GroupedServices.filter(x => x.EmployeeId != Id).remove();
vm.filteredSerivces(filteredSrvcs );
But I changed structure in that way, and my bindings in html is not corresponding.
Is there any other way to just remove this sub-sub object, and to preserve a structure as it is?
Here is the
Here's an example that maps a new array of new objects and the filter is set to only include the GroupedServices items where Id == 2000
let res = data.map(({ServiceTypeName, GroupedServices}) =>{
GroupedServices= GroupedServices.filter(({Id}) => Id == 2000);
return {ServiceTypeName,GroupedServices }
})
console.log(res)
<script>
let data =
[
{
"ServiceTypeName": "Type 1",
"GroupedServices": [{
"Id": 1,
"Name": "A"
}, {
"Id": 2,
"Name": "A"
},
{
"Id": 28456,
"Name": "AGSADGJS"
}]
},
{
"ServiceTypeName": "Type 2",
"GroupedServices": [{
"Id": 1203,
"Name": "AHASJ"
}, {
"Id": 2000,
"Name": "AHSJD"
},
{
"Id": 284536,
"Name": "UEHNCK"
}]
}];
</script>
I have two arrays:
const array1 = [{
"id": "4521",
"name": "Tiruchirapalli",
"stateId": "101"
},
{
"id": "1850",
"name": "Tenkasi",
"stateId": "101"
},
{
"id": "202",
"name": "Thanjavur",
"stateId": "101"
},
{
"id": "505",
"name": "Ernakulam",
"stateId": "102"
},
];
And now array2
const array2 = [{
"id": 1850,
"cityName": "Tenkasi",
"aliasNames": [
"Thenkasi"
]
},
{
"id": 4521,
"cityName": "Tiruchirapalli",
"aliasNames": [
"Trichy"
]
},
{
"id": 202,
"cityName": "Thanjavur",
"aliasNames": [
"Tanjore"
]
},
{
"id": 505,
"cityName": "Ernakulam",
"aliasNames": [
"Kochi",
"Cochin"
]
},
];
what i need to do is, how to filter both the arrays at same time ( or filter first one and then second which ever one is performance effective ).
For instance, when user types "Kochi", first it should check on array1 to find if its has name="Kochi", if it has then we can set the state with that and if it doesnt have we need to find it on array2 and the update the state !
Which is fast and effective way to handle this - ( array1 has 2500 records and array2 has 990 records ) so performance / speed is also a concern
My attempt:
searchFilterFunction = text => {
this.setState({ typedText: text });
const newData = array1.filter(item => {
const itemData = `${item.name.toUpperCase()}`;
const textData = text.toUpperCase();
return itemData.indexOf(textData) > -1;
});
this.setState({ data: newData});
};
How to implement the second filter in optimized way ?
For instance, when user types "Kochi", first it should check on array1
to find if its has name="Kochi", if it has then we can set the state
with that and if it doesnt have we need to find it on array2 and the
update the state !
I would do something like this with Array.find.
if( array1.find(item=>item.name.toUpperCase() === text) ) {
// set state
} else if( array2.find(item=>item.cityName.toUpperCase() === text) ) {
// set state
}
A refined form would be
let result = array1.find(item=>item.name.toUpperCase() === text);
// check in array 2 as we cannot find in array 1
if(!result) {
result = array2.find(item=>{
// check in aliasNames and in cityName
return item.cityName.toUpperCase() === text || item.aliasNames.includes(text);
}
);
}
if(result) {
setState(result);
} else {
// place not found
}
Regarding the performance based on your array count you will not see much difference. If you want to save some milliseconds you can check the array with least count first as mentioned in one of the comments. But the time also varies based on were the element is in array.
I think this is the most optimal solution because nesting the two filter won't work as you need to filter from first array and then second.
const array1 = [{
"id": "4521",
"name": "Tiruchirapalli",
"stateId": "101"
},
{
"id": "1850",
"name": "Tenkasi",
"stateId": "101"
},
{
"id": "202",
"name": "Thanjavur",
"stateId": "101"
},
{
"id": "505",
"name": "Ernakulam",
"stateId": "102"
},
];
const array2 = [{ "id": 1850, "cityName": "Tenkasi",
"aliasNames": [
"Thenkasi"
]
},{"id": 4521,"cityName": "Tiruchirapalli",
"aliasNames": [
"Trichy"
]
},
{
"id": 202,
"cityName": "Thanjavur",
"aliasNames": [
"Tanjore"
]
},
{
"id": 505,
"cityName": "Ernakulam",
"aliasNames": [
"Kochi",
"Cochin"
]
},
];
function filter(text) {
// Complexity Linear
const filter_array = array1.filter((a) => {
return (a.name === text)
});
if (filter_array.length > 0) {
//Set State and return
}
//Complexity Linear and includes complexity Linear O(sq(m*n)) where n is //the aliasName record
const filter_array2 = array2.filter((a) => {
return a.cityName === text || a.aliasNames.includes(text);
});
return filter_array2 //Set State filter array 2
}
console.log(filter("Kochi"));
I have data from backend in my js like this:
var list = {
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
},
};
Then I need to display this data in my angular html template through ngFor directive. But first I have to get an array of object keys:
var listKeys= Object.keys(list);
Next I can output data in template:
<div *ngFor="let item of listKeys">
<p>{{list[item].id}}</p>
<p>{{list[item].name}}</p>
<p>{{list[item].age}}</p>
<hr>
</div>
But the problem is that order of my data changed. I have in listKeys next array ["3", "6", "42"]. But I want to have original order in that one ["6", "42", "3"]. One of solutions that I have found is make keys as not numeric string. For example:
var list = {
"+6": {...},
"+42": {...},
"+3": {...},
};
But I don't have access to backend. I need another solution.
P.S. The way in which I get data from the backend
getData() {
this._dataService.getList(this.name, this.age).subscribe(res => {
this.list = JSON.parse(JSON.stringify(res));
this.listKeys = Object.keys(this.list);
});
}
By definition, an object is an unordered collection of properties. As a solution, you could use an array instead of an object:
The first step would be to convert the response from the server to an array in the same order.
// Original JSON string received from API
var jsonString = `{
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
}
}`;
// Array of ordered id's
const orderedIds = [];
// Find all id's in the JSON string and push them to the array
const pattern = /"?id"?\: (\d*)/g;
let match;
while (match = pattern.exec(jsonString)) {
orderedIds.push(parseInt(match[1]));
}
// parse the original JSON object
const originalList = JSON.parse(jsonString);
// resulting ordered Array
const result = [];
// Push the object in the array by order
for(x of orderedIds) {
result.push(originalList[x]);
}
// Log the resulting array
document.getElementById("result").innerText = JSON.stringify(result);
<pre id="result"></pre>
The result will be an array of the objects in the same order as they appeared in the JSON string:
result = [
{
"id": 6,
"name": "John",
"age": 31
},
{
"id": 42,
"name": "Alex",
"age": 25
},
{
"id": 3,
"name": "Tim",
"age": 58
},
];
After this you can use it in your template:
<div *ngFor="let item of result">
<p>{{item.id}}</p>
<p>{{item.name}}</p>
<p>{{item.age}}</p>
<hr>
</div>
this array does garantee the order of its values.
This is bound to have edge cases, but adding it because it works
If you are getting the data from the backend in the form of JSON then you can do the following
note: var json is a placeholder, as you haven't shown HOW you get your data
var json = `{
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
}
}`;
var result = JSON.parse(json.replace(/\s?"(\d+)":/g, '"$1 ":'));
console.log(Object.keys(result));
Again, this is bound to fail, but I can't see any other way you can "fix" this on the client side - I thought JSON.parse "reviver" function would help, but it gets the properties in 3, 6, 42 order as well - so, no use at all
I want combine a JSON object to an ARRAY.
I would like retrieve data from keys finded on var product, and combine score finded to a new variable ( combined results )
combinedresults is what I need. I absolutely don't know how to do this
var product = {
"presentation": 3,
"imgmax": http://test.com/img.jpg,
"puissance": 5,
"efficacite": 4,
"description": "This product is awesome but i need to combine JSON results"
}
var array = [
{
"caracname": "presentation",
"name": "Présentation"
},
{
"caracname": "efficacite",
"name": "Efficacité"
},
{
"caracnam": "puissance",
"name": "Puissance"
}
]
var combinedresults = [
{
"caracname": "presentation",
"name": "Présentation",
"score": 3
},
{
"caracname": "efficacite",
"name": "Efficacité",
"score": 4
},
{
"caracnam": "puissance",
"name": "Puissance",
"score": 5
}
]
Iterate through each item of the array, if the product object contains a key that matches the current items caracname, add it's value as a score.
See below:
var product = {
"presentation": 3,
"imgmax": "http://test.com/img.jpg",
"puissance": 5,
"efficacite": 4,
"description": "This product is awesome but i need to combine JSON results"
}
var array = [
{
"caracname": "presentation",
"name": "Présentation"
},
{
"caracname": "efficacite",
"name": "Efficacité"
},
{
"caracname": "puissance",
"name": "Puissance"
}
]
array.forEach(function(item) {
if (product[item.caracname]) {
item.score = product[item.caracname];
}
});
console.log(array);
Simply map over your current array, extending every object with the score attribute.
array.map(obj => ({...obj, score: product[obj.caracname]}));
If you are not familiar, consider having a look at the spread operator;
I am working on a solution where I need to search for an element in a deeply nested JSON by its id. I have been advised to use underscore.js which I am pretty new to.
After reading the documentation http://underscorejs.org/#find , I tried to implement the solution using find, filter and findWhere.
Here is what I tried using find :
var test = {
"menuInputRequestId": 1,
"catalog":[
{
"uid": 1,
"name": "Pizza",
"desc": "Italian cuisine",
"products": [
{
"uid": 3,
"name": "Devilled chicken",
"desc": "chicken pizza",
"prices":[
{
"uid": 7,
"name": "regular",
"price": "$10"
},
{
"uid": 8,
"name": "large",
"price": "$12"
}
]
}
]
},
{
"uid": 2,
"name": "Pasta",
"desc": "Italian cuisine pasta",
"products": [
{
"uid": 4,
"name": "Lasagne",
"desc": "chicken lasage",
"prices":[
{
"uid": 9,
"name": "small",
"price": "$10"
},
{
"uid": 10,
"name": "large",
"price": "$15"
}
]
},
{
"uid": 5,
"name": "Pasta",
"desc": "chicken pasta",
"prices":[
{
"uid": 11,
"name": "small",
"price": "$8"
},
{
"uid": 12,
"name": "large",
"price": "$12"
}
]
}
]
}
]
};
var x = _.find(test, function (item) {
return item.catalog && item.catalog.uid == 1;
});
And a Fiddle http://jsfiddle.net/8hmz0760/
The issue I faced is that these functions check the top level of the structure and not the nested properties thus returning undefined. I tried to use item.catalog && item.catalog.uid == 1; logic as suggested in a similar question Underscore.js - filtering in a nested Json but failed.
How can I find an item by value by searching the whole deeply nested structure?
EDIT:
The following code is the latest i tried. The issue in that is that it directly traverses to prices nested object and tries to find the value. But my requirement is to search for the value in all the layers of the JSON.
var x = _.filter(test, function(evt) {
return _.any(evt.items, function(itm){
return _.any(itm.outcomes, function(prc) {
return prc.uid === 1 ;
});
});
});
Here's a solution which creates an object where the keys are the uids:
var catalogues = test.catalog;
var products = _.flatten(_.pluck(catalogues, 'products'));
var prices = _.flatten(_.pluck(products, 'prices'));
var ids = _.reduce(catalogues.concat(products,prices), function(memo, value){
memo[value.uid] = value;
return memo;
}, {});
var itemWithUid2 = ids[2]
var itemWithUid12 = ids[12]
I dont use underscore.js but you can use this instead
function isArray(what) {
return Object.prototype.toString.call(what) === '[object Array]';
}
function find(json,key,value){
var result = [];
for (var property in json)
{
//console.log(property);
if (json.hasOwnProperty(property)) {
if( property == key && json[property] == value)
{
result.push(json);
}
if( isArray(json[property]))
{
for(var child in json[property])
{
//console.log(json[property][child]);
var res = find(json[property][child],key,value);
if(res.length >= 1 ){
result.push(res);}
}
}
}
}
return result;
}
console.log(find(test,"uid",4));