Im trying to merge 2 data sources in 1, I wanna loop through them and if a specefic value matches than add it to the first object with the same value and add the in the emty array what is already there. No matter how much objects I have.
So lets say I have this information
Source 1
one = {
"teams": [
{
name: 'ABC',
members: [],
rooms: '0'
},
{
name: 'DEF',
members: [],
rooms: '1'
}
]
}
Source 2
two = {
"persons": [
{
name: 'Foo',
gender: 'male',
room: '1'
},
{
name: 'Bar',
gender: 'female',
room: '2'
}
]
}
And what I want is that the 'persons' array merge to the members array if the 'room and rooms' value matches.
What I would assume is something similar like this:
for(var i = 0 ; i < two.persons.length; i++) {
if (one.teams[i].rooms == two.persons[i].room) {
data.teams[i].members.push(two.persons[i]);
}
}
using higher order methods you can do:
one = {
"teams": [
{
name: 'ABC',
members: [],
rooms: '0'
},
{
name: 'DEF',
members: [],
rooms: '1'
}
]
};
two = {
"persons": [
{
name: 'Foo',
gender: 'male',
room: '1'
},
{
name: 'Bar',
gender: 'female',
room: '2'
}
]
};
var ttt = one.teams.map(function(x){
var roomVal= x.rooms;
x.members = two.persons.filter(function(t){
return t.room == roomVal});
return x;
})
one.teams = ttt;
console.log(one)
The problem with your code is that once you iterate the two array, then you do not go back and see if the previous element matched with the current one.
For example, if [0] on each arrays does not match and you iterate to index [1] in the for-loop, you do not have a way to check if two[1] matched one[0].
To do a complete search, you could directly iterate the arrays for each value of two:
two.persons.forEach(function(person) {
one.teams.forEach(function(team) {
if (team.rooms == person.room) {
team.members.push(person);
}
});
});
There are many strategies to do this. But most important you should iterate each array separately. I would use an Array.forEach();
one.teams.forEach(function (team, teamsIndex, teamsArray) {
two.persons.forEach(function (person, personsIndex, personsArray) {
if (team.room == person.room) {
// Do what you need to do.
}
});
});
Didn't check syntax so be aware to read Array.forEach(); documentation.
Related
I have a js file that is just a an array with the name and type of person. I am trying to write a function in my other file to iterate through that array of objects and return just the object that matches a certain criteria. Here is my code.
person.js
export const persons_options = [
{
name: 'Andrew',
type: 'Athlete',
},
{
name: 'Paul',
type: 'Worker',
},
{
name: 'Phil',
type: 'Developer',
},
]
utils.js
// params initialized already
person_type = params.subType
const name = persons_options.map((option) => {
if(person_type === option.type){
return option.name
}
})
const person = name
The issue is I know map creates a new array so the output is ,,Phil. How would I just return one of the object names instead of all of them.
find() will do the work
let persons_options = [
{
name: 'Andrew',
type: 'Athlete',
},
{
name: 'Paul',
type: 'Worker',
},
{
name: 'Phil',
type: 'Developer',
},
]
let obj = persons_options.find(o => o.type === 'Developer');
//to return name
console.log("name",obj.name);
console.log(obj);
You need to use the find function.
See here the list of functions that you can call on an array:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array#instance_methods
filter might best suit your case if multiple results may be returned.
Can someone help me generate a new array of objects from an existing one using lodash? I've been trying a combination of _.zipObject and map but to no avail... basically, I have an array of objects like:
const names = [
{
first_name: 'nedd',
given_name: 'cersei'
},
{
first_name: 'tyrion',
given_name: 'tywin'
}
]
However, I want it to look like:
[
{
name: 'nedd'
},
{
name: 'cersei'
},
{
name: 'tyrion'
},
{
name: 'tywin'
},
]
I have tried various iterations of:
const newArray = _.zipObject( names, _.fill( Array(names.length), {name: ['first_name' || 'given_name']} ) );
But without any luck... can someone help?
Thanks in advance!
This might work:
_.flatMap(names, (n)=> [{name: n.first_name}, {name: n.given_name}]);
Use _.flatMap combined with _.map:
_.flatMap(names, (nameObj) => _.map(nameObj, (objVal) => { return { name: objVal }; }));
I have this array:
var myArray = [
{ familyName: 'one', subfamilies:
[ { subfamilyName: 'subOne', subItems:
[ { name: 'subOne', code: '1' },
{ name: 'subTwo', code: '2' }
] }
]
},
{ familyName: 'two', subfamilies:
[ { subfamilyName: 'subTwo', subItems:
[ { name: 'subOne', code: '1' },
{ name: 'subTwo', code: '2' },
{ name: 'subTwo', code: '3' }
] }
]
}
]
I need to divide that array in two diferent arrays with the same length if possible (my real array is so much longer), but I am having some problems getting it done. I create 2 blank array and, with for sentence read all the items. First I push the subItems in one blank array, but cannot get the way to create a new subFamily in a blank array variable and then push the sutItems array.
How can be this done?
Thanks a lot in advance.
var myOtherArray = myArray.splice(myArray.length / 2 | 0);
I have an array of object and I want to count the number of distinct elements and counts of those objects.
[ { name: 'Suman',
game: '5A'
},
{ name: 'Suman',
game: '5A'
},
{ name: 'Namus',
game: '5A'
},
{ name: 'Namus',
game: '5A'
}
]
I want to count the number of distinct names and store them in an object. I have tried it by 1# pushing all the names in an array,
2# then sorting them,
3# then calculating the number of distinct names and
4# finally pushing them to the object.
This process is too long. Is there a shorter way to do this. I am using Nodejs
Thanks in advance
You will create a new object, where the key is the name and the value the count:
var youArr = [
{ name: 'Suman',
game: '5A'
},
{ name: 'Suman',
game: '5A'
},
{ name: 'Namus',
game: '5A'
},
{ name: 'Namus',
game: '5A'
}
];
var count = {}
for(var i=0; i < youArr.length; i++){
count[youArr[i].name] = count[youArr[i].name] || 0;
count[youArr[i].name]++;
}
alert(count['Namus']); // 2
This is a great place to use the reduce function:
The reduce() method applies a function against an accumulator and each
value of the array (from left-to-right) has to reduce it to a single
value.
...
reduce executes the callback function once for each element present in
the array, excluding holes in the array, receiving four arguments: the
initial value (or value from the previous callback call), the value of
the current element, the current index, and the array over which
iteration is occurring.
It would look something like this:
var arr = [ { name: 'Suman',
game: '5A'
},
{ name: 'Suman',
game: '5A'
},
{ name: 'Namus',
game: '5A'
},
{ name: 'Namus',
game: '5A'
}
]
var counts = arr.reduce(function(counts, item) {
counts[item.name] = (counts[item.name] || 0) + 1;
return counts;
}, {});
counts is then:
{ Suman: 2, Namus: 2 }
Asked in the comments:
what if i want the count as well as name in an array of object like
[{name: 'Suman', count:'2'}, {name:'Namus', count:'2'}]
If you already have counts from the reduce call above, then you can map its keys to the format you want:
var countsArray = Object.keys(counts).map(function(name) {
return {name: name, count: counts[name]};
});
countsArray is then:
[ { name: 'Suman', count: 2 },
{ name: 'Namus', count: 2 } ]
I am trying to learn JS. It seems simple but I am not sure how to do this.
having this javascript object based on this good
thread
var people = {
1: { name: 'Joe' },
2: { name: 'Sam' },
3: { name: 'Eve' }
};
How do I add the following value 4: { name: 'John' }
To get name Eve I write
people["1"].name
Assign the anonymous object to it the way you would any other value.
people["4"] = { name: 'John' };
For what it's worth, since your keys are numeric you could also use zero-based indices and make people an array.
var people = [ { name: 'Joe' },
{ name: 'Sam' },
{ name: 'Eve' } ];
and
alert( people[2].name ); // outputs Eve
people[3] = { name: 'John' };
I think people should be an array :
var people = [
{ name: 'Joe' },
{ name: 'Sam' },
{ name: 'Eve' }
];
as the keys are integers, so you can add a person by :
people.push({name:'John'});
You can acces to the people by doing :
var somebody = people[1]; /// >>> Sam