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what can i do i got out when i am searching class then count how many student in class

let student = [{
id:1,
name:'aman',
class:'10',
gender:'male'
},{
id:2,
name:'shivani',
class:'10',
gender:'female'
},{
id:2,
name:'riyan',
class:'11',
gender:'female'
}]
function customFilter(objList, text){
if(undefined === text || text === '' ) return objList;
return objList.filter(product => {
let flag;
for(let prop in product){
if(product[prop].toString().indexOf(text)>-1){
product[prop] = 0
product[prop]++
flag = product[prop]
console.log(flag)
}
}
return flag;
});}
console.log( customFilter(student, '10'))
I want the output of the number of students in a class. Example: when I pass class 10 as an argument then i should get output how many students in class 10
output:
{class:10,stduent:5 }

I didn't get your question well, but I assumed you want number of student in a class like this {class:10, students: 2}
let student = [
{ id:1, name:'aman', class:'10', gender:'male'},
{ id:2, name:'shivani', class:'10', gender:'female' },
{ id:3, name:'riyan', class:'11', gender:'female' }
]
function customFilter(objList, text){
if(undefined === text || text === '' ) return objList;
const numberOfStudents = objList.filter(product => {
for (let prop in product) {
if (product[prop].toString().includes(text)) {
return true;
}
}
});
return {class:text, student:numberOfStudents.length }
}
console.log( customFilter(student, '10'))
If that's the case this code will do , hope it helps

This would also work:
let students = [
{ id: 1, name: "aman", class: "10", gender: "male" },
{ id: 2, name: "shivani", class: "10", gender: "female" },
{ id: 2, name: "riyan", class: "11", gender: "female" },
];
const customFilter = (students, key, value) => {
const res = { [key]: value, student: 0 };
students.forEach((student) => {
if (student[key] === value) {
res.student += 1;
}
});
return res;
};
console.log(customFilter(students, "class", "10"));
Using Array.prototype.forEach()

There are few problems with the code. change class:'10' to grade: 10,.
don't use "class" as a variable name. might cause a few errors
There is a missing ,
numbers shouldn't be inside quotes because the number will be stored as a string
let student = [
{ id: 1, name: 'aman', grade: 10, gender: 'male'},
{ id: 2, name: 'shivani', grade: 10, gender: 'female' },
{ id: 2, name: 'riyan', grade: 11, gender: 'female' },
]
function customFilter(objList, value){
if(!value || value === '') return objList;
let count = 0
objList.forEach(obj => {
const { grade } = obj;
if(grade === value){
count++;
}
})
return {grade: 10, count};
}
console.log(customFilter(student, 10));
and forEach can be used instead of filter. It loops from start to end of an array

Use .reduce() to group all objects that match.
/* hits (accumulator) is initially an empty array.
now (current) is the object of the current iteration. */
array.reduce((hits, now) => { //...
On each iteration, get all of the current object's values (in lower case) in an array.
Object.values(now).map(val => val.toLowerCase())
/* result of the first object: ["01gn3z1ryjjqhn588ax3bws6qb", "theo bramstom",
"genderqueer", "english"] */
If any of the values of the current object matches the given string (term), add the current object to the hits array.
if (Object.values(now)
.map(val => val.toLowerCase()).includes(term.toLowerCase())) {
hits.push(now);
}
An object literal is returned.
{
"matches": /* an array of all matched objects */,
"total": /* the .length of "matches" array */
};
/* To get the answer prompted in OP -- do the following */
const x = dataFilter(students, "Math");
console.log(x.total);
// NOTE: key "class" is now "subject" just for aesthetics
const students=[{id:"01GN3Z1RYJJQHN588AX3BWS6QB",name:"Theo Bramstom",gender:"Genderqueer",subject:"English"},{id:"01GN3Z1RYM527HAX56ZN14F0YB",name:"Juli Marsy",gender:"Female",subject:"History"},{id:"01GN3Z1RYPYP1FFFEY55T92VX2",name:"Linc Espley",gender:"Non-binary",subject:"Math"},{id:"01GN3Z1RYR325M0QETVVPE2N5J",name:"Barbabas Grisley",gender:"Male",subject:"Math"},{id:"01GN3Z1RYTXA49SBQYXR9DMC04",name:"Godfree Braybrook",gender:"Male",subject:"English"},{id:"01GN3Z1RYVE4N5D16C8QWB1XGF",name:"Jason De Vuyst",gender:"Male",subject:"History"},{id:"01GN3Z1RYXY9WXF1Y407HXFYH8",name:"Adler McCanny",gender:"Male",subject:"Math"},{id:"01GN3Z1RYY9XV444J0SP5Y0QC2",name:"Noellyn MacMorland",gender:"Genderqueer",subject:"Math"},{id:"01GN3Z1RZ0HPQNZ1VKX8ZHA9ZY",name:"Padget Geldeford",gender:"Male",subject:"Math"},
{id:"01GN3Z1RZ2DZE92NG42KSGDXN9",name:"Milissent Treby",gender:"Female",subject:"Art"}];
const dataFilter = (array, term) => {
let result = array.reduce((hits, now) => {
if (Object.values(now).map(val => val.toLowerCase()).includes(term.toLowerCase())) {
hits.push(now);
}
return hits;
}, []);
return {"matches": result, "total": result.length};
}
console.log(dataFilter(students, "Math"));
// Control case: term === "Math"
console.log(dataFilter(students, "PE"));
// No match case: term != "PE"
console.log(dataFilter(students, "female"));
// Case insensitive case: term === "Female"

Joining nested individual properties by comma

I am trying to join the array of objects internal properties with the comma , like as below
const multiSpaceIdentityInformation = spaces?.reduce(
(acc, space) => {
acc.roomName = `${acc.roomName},${space.spaceIdentity.roomName}`;
acc.roomNumber = `${acc.roomNumber},${space.spaceIdentity.roomNumber}`;
acc.storyName = `${acc.storyName},${space.buildingStory?.name}`;
acc.spaceNumber = `${acc.spaceNumber},${space.spaceIdentity.number}`;
acc.spaceName = `${acc.spaceName},${space.spaceIdentity.name}`;
return acc;
},
{
roomName: 'N/A',
roomNumber: 'N/A',
storyName: 'N/A',
spaceNumber:'N/A',
spaceName: 'N/A'
}
);
But somehow, I cannot display the information even I have spaces holding the array of objects.
What I am trying to display is if there is no information, I would like to say 'N/A' as the default option.
I am accessing the above information here
const identityData = [
{ label: 'Room Number', value: multiSpaceIdentityInformation.roomNumber },
{ label: 'Room Name', value: multiSpaceIdentityInformation.roomName },
{ label: 'Level', value: multiSpaceIdentityInformation.storyName },
{ label: 'Space Number', value: multiSpaceIdentityInformation.spaceNumber },
{ label: 'Space Name', value: multiSpaceIdentityInformation.spaceName }
];
Could anyone please let me know where it goes wrong with the above code?
Many thanks in advance!
Sample input
{
"Spaces": [
{
"spaceGeometry":{
"roomName": ""
"roomNumber": "",
"number": "number1"
"name": "space1"
},
"buildingStory":{
"name": "story1"
}
},
{
"spaceGeometry":{
"roomName": ""
"roomNumber": "",
"number": "number2"
"name": "space2"
},
"buildingStory":{
"name": "story2"
}
},
]
}
and desired output be like
multiSpaceIdentityInformation.roomName = "N/A"
multiSpaceIdentityInformation.roomNumber = "N/A"
multiSpaceIdentityInformation.storyName = "story1, story2"
multiSpaceIdentityInformation.spaceNumber = "number1, number2"
multiSpaceIdentityInformation.spaceName = "space1, space2"

The second parameter of reduce() is the initial value, so "N/A" will be rendered as long as spaces is an array. Here's what I would do:
const appendData = (initialValue, newValue) => {
if(!newValue) return initialValue;
if(!initialValue || initialValue === '') return newValue;
return `${initialValue}, ${newValue}`;
}
const multiSpaceIdentityInformation = spaces?.reduce(
(acc, space) => ({
roomName: appendData(acc.roomName, space.spaceIdentity.roomName),
roomNumber: appendData(acc.roomNumber, space.spaceIdentity.roomNumber),
storyName: appendData(acc.storyName, space.buildingStory?.name),
spaceNumber: appendData(acc.spaceNumber, space.spaceIdentity.number),
spaceName: appendData(acc.spaceName, space.spaceIdentity.name)
}),
{
roomName: '',
roomNumber: '',
storyName: '',
spaceNumber:'',
spaceName: ''
}
);
Object.keys(multiSpaceIdentityInformation).forEach((key) => {
if(multiSpaceIdentityInformation[key] === '')
multiSpaceIdentityInformation[key] = 'N/A';
});

map an array inside object of an array

So I have an array of objects with many, keys, something like that:
[
{ id: 1,
phoneNumber: 12345,
name: "John",
underLicense: true
},
{ id: 2,
phoneNumber: 12345,
name: "Jane",
underLicense: false
}
]
The way i want it to look like is this:
[
{ listPhone: [
{ number: 12345,
underLicense: true
},
{ number: 12345
underLicense: false
}
]
}
]
so for that, first i do the map(), and then I push it into listPhones
here is my function
saveLicense() {
const listPhone = this.toSend.map(x => {
return {
number: x.phoneNumber,
underLicense: x.underLicense
};
});
const savedPhones = [];
savedPhones.push({listPhone: listPhone});
}
The question is, is there a way to to it in the map() metod, without having to use push in the second step

You could directly map to an expression for a property value.
saveLicense() {
const
savedPhones = [{ listPhone: this.toSend.map(({ phoneNumber: number, underLicense }) =>
({ number, underLicense })
) }];
}

Maybe:
saveLicense () {
const listPhone = this.toSend.map((x) => ({
number: x.phoneNumber,
underLicense: x.underLicense,
}));
const savedPhones = [{ listPhone }];
};

saveLicense() {
const listPhone = this.toSend.map(x => {
return { listPhone: {
number: x.phoneNumber,
underLicense: x.underLicense
}
};
});
return [listPhone]
}

array some is not working in nested array

I want to check if current user is present in nested array or not.
this is few part of my sample array which is getting from API:
[
{
"owner":"abc",
"_id":"xyz77",
"comments":[
],
"likes":[
{
"_id":"9999",
"username":"user1"
},
{
"_id":"9998",
"username":"user2"
}
]
},
{
"owner":"bcd"
}
]
I want to see if user1 is present in likes array or not.
if yes then it should give output like this:
[
{
"owner":"abc",
"user1":true
},
{
"owner":"bcd",
"user1":true
},
{
"owner":"def",
"user1":false
}
]
above result is likes array of owner abc has user1 but not present in owner def.
I tried with array.some for likes array inside forEach of owner array. But not getting proper result.
help is appreciated

You can use a combination of Array.prototype.map and Array.prototype.some to create a resulting array which checks if any of the users in the likes array of each owner object matches your username:
const data = [
{
"owner":"abc",
"_id":"xyz77",
"comments":[],
"likes":[
{
"_id":"9999",
"username":"user1"
},
{
"_id":"9998",
"username":"user2"
}
]
},
{
"owner":"bcd",
"_id":"xyz88",
"comments":[],
"likes":[
{
"_id":"9998",
"username":"user2"
},
{
"_id":"9997",
"username":"user3"
}
]
},
];
const checkUsername = (data, username) => {
return data.map(e => {
const x = { owner: e.owner };
x[username] = e.likes.some(el => el.username === username);
return x;
});
};
console.log(checkUsername(data, 'user1'));
console.log(checkUsername(data, 'user2'));

Its Similar to #awarrier99 answer, Use destructuring along with map and some.
const data = [
{
owner: "abc",
_id: "xyz77",
comments: [],
likes: [
{
_id: "9999",
username: "user1",
},
{
_id: "9998",
username: "user2",
},
],
},
{
owner: "bcd",
},
];
const update = (arr, user) =>
data.map(({ likes = [], owner }) => ({
[user]: likes.some(({ username }) => username === user),
owner,
}));
console.log(update(data, "user1"));

Comparing objects in two arrays

I want to compare objects in two arrays and if they are not the same, add them to the array.
first array
[
{
"email": "a#a.com"
},
{
"email": "b#b.com"
},
{
"email": "c#c.com"
},
{
"email": "d#d.com"
}
]
secund array
[
{
"email": "v#v.com"
},
{
"email": "k#k.com"
},
{
"email": "g#g.com"
}
]
checking function
if($scope.participants.length > 0){
result.forEach(function (resultElement) {
if(!$scope.participants.includes(resultElement) ) {
$scope.participants.push(resultElement);
}
})
result = [];
console.log($scope.participants);
}
I checked the debug and it drops on the if condition.

You need to understand that two objects are not equal and the same.
For example {} === {} returns false
if you want to compare objects you need to compare each primitive element of each object.
Primitives include numbers, strings, booleans, etc and not objects or arrays (which are also objects).

b1 = [
{ id: 0, email: 'john#' },
{ id: 1, email: 'mary#' },
{ id: 2, email: 'pablo#' },
{ id: 3, email: 'escobar#' }
];
b2 = [
{ id: 0, email: 'john#' },
{ id: 1, email: 'mary#' }
];
var res = this.b1.filter(item1 =>
!this.b2.some(item2 => (item2.id === item1.id && item2.name === item1.name)))
console.log("check more is working",res);