I have an array of country such as:
country=["Afganistan","Albania","Algeria"]
How can I convert this array into array of objects such as:
newarray=[
{ key: 'Afghanistan', value: 'Afghanistan', text: 'Afghanistan' },
{ key: 'Albania', value: 'Albania', text: 'Albania' },
{ key: 'Algeria', value: 'Algeria', text: 'Algeria' }
]
country=["Afganistan","Albania","Algeria"]
let newarray = [];
country.forEach(item => {
newarray.push({
key: item,
value: item,
text: item
});
});
console.log(newarray);
I found the answer. The method will be:-
let newarray = [];
country.map(item => {
return newarray.push({ key: item, value: item, text: item })
})
Related
I have a JSON array, which looks as follows.
[
{
id: 1,
name: 'Alex',
activity: [
{
id: 'A1',
status: true
},
{
id: 'A2',
status: true
},
{
id: 'A3',
status: false
}
]
},
{
id: 2,
name: 'John',
activity: [
{
id: 'A6',
status: true
},
{
id: 'A8',
status: false
},
{
id: 'A7',
status: false
}
]
}
]
I want to get an array of activity id whose status should be true.I can achieve this with nester for or forEach loop. But here I am looking to achieve with the help of array functions like filter, map, and some.
I have already tried with the following.
let newArr=arr.filter(a=> a.activity.filter(b=> b.status).map(c=> c.id))
But I didn't get the correct answer
Expected output
['A1','A2','A6']
function filter_activity(activities) {
return activities
&& activities.length
&& activities.map(x => x.activity)
.flat().filter(activity => activity.status)
.map(x => x.id) || [];
}
Illustration
function filter_activity(activities) {
return activities &&
activities.length &&
activities.map(x => x.activity)
.flat().filter(activity => activity.status)
.map(x => x.id) || [];
}
const input = [{
id: 1,
name: 'Alex',
activity: [{
id: 'A1',
status: true
},
{
id: 'A2',
status: true
},
{
id: 'A3',
status: false
}
]
},
{
id: 2,
name: 'John',
activity: [{
id: 'A6',
status: true
},
{
id: 'A8',
status: false
},
{
id: 'A7',
status: false
}
]
}
];
console.log(filter_activity(input));
WYSIWYG => WHAT YOU SHOW IS WHAT YOU GET
let arr = json.flatMap(e => e.activity.filter(el => el.status).map(el => el.id))
let newArr=arr.map(x => x.activity)
.reduce((acc, val) => acc.concat(val), [])
.filter((activity:any) => activity.status)
.map((x:any) => x.id) || [];
I got error when using flat() and flatMap().So, I have used reduce().
I want to create data from DATA to OPTIONS.
const DATA = [
{ name: 'aaa', id: 'happy' },
{ name: 'bbb', id: 'time' },
{ name: 'ccc', id: 'party' },
];
const OPTIONS =[{value:'aaa', label:'aaa'},
{value:'bbb', label:'bbb'},
{value:'ccc', label:'ccc'},
]
I need only name value in DATA.
so, using name value, I want to create OPTIONS.
Fuction Test(){
const DATA = [
{ name: 'aaa', id: 'happy' },
{ name: 'bbb', id: 'time' },
{ name: 'ccc', id: 'party' },
];
const OPTIONS =[{value:'aaa', label:'aaa'},
{value:'bbb', label:'bbb'},
{value:'ccc', label:'ccc'},
]
}
let newObject=[];
const createData = () => {
const arr = selectMainId.data.map(data => data.name);
arr.map(data => newObject.push({ value: data, label: data }));
console.log('newObj:', newObject);
};
console.log('newObj1:', newObject))
this case, I can get OPTIONS same data.
so, I can get newObject in createData console.
but I can't get newObject in Test console.
I don't know this issue.
Do you know effective way?
please help me.
The map() method creates a new array populated with the results of calling a provided function on every element in the calling array.
Clean and simplest way:
const DATA = [
{ name: 'aaa', id: 'happy' },
{ name: 'bbb', id: 'time' },
{ name: 'ccc', id: 'party' },
];
const OPTIONS = DATA.map(x => ({value: x.name, label: x.name }));
console.log(OPTIONS);
You just need to do
const createData = (data) => {
return data.map(d => ({name: data.name, label: data.name}))
};
const option = createData(data)
Given is following data structure
const list = [
{
title: 'Section One',
data: [
{
title: 'Ay',
},
{
title: 'Bx',
},
{
title: 'By',
},
{
title: 'Cx',
},
],
},
{
title: 'Section Two',
data: [
{
title: 'Ay',
},
{
title: 'Bx',
},
{
title: 'By',
},
{
title: 'Cx',
},
],
},
];
What i want to do ist to filter this list based on title property in the data array of each object.
An example would be to have the list where the title property of the childs starts with "B", so the list will look like that:
const filteredList = [
{
title: 'Section One',
data: [
{
title: 'Bx',
},
{
title: 'By',
}
],
},
{
title: 'Section Two',
data: [
{
title: 'Bx',
},
{
title: 'By',
}
],
},
];
What i tried so far was something like that:
const items = list.filter(item =>
item.data.find(x => x.title.startsWith('A')),
);
or
const filtered = list.filter(childList => {
childList.data.filter(item => {
if (item.title.startsWith('B')) {
return item;
}
return childList;
});
});
But i think i am missing a major point here, maybe some of you could give me a tip or hint what i am doing wrong
Best regards
Your issue is that you're doing .filter() on list. This will either keep or remove your objects in list. However, in your case, you want to keep all objects in list and instead map them to a new object. To do this you can use .map(). This way you can map your objects in your list array to new objects which contain filtered data arrays. Here's an example of how you might do it:
const list=[{title:"Section One",data:[{title:"Ay"},{title:"Bx"},{title:"By"},{title:"Cx"}]},{title:"Section Two",data:[{title:"Ay"},{title:"Bx"},{title:"By"},{title:"Cx"}]}];
const filterByTitle = (search, arr) =>
arr.map(
({data, ...rest}) => ({
...rest,
data: data.filter(({title}) => title.startsWith(search))
})
);
console.log(filterByTitle('B', list));
I have an array object
MainArray = {"Data":
[{"Group": "GroupA"},{"Group": "GroupB"}]
}
then I loop through the array and created a new
let _newArray : any[] = [];
MainArray.Data.forEach(item => {
_newArray.push({
groupname : item.Group,
columns: ["column1","column2","column3"]
});
//loop through _newArray.columns
});
then I need to loop through the columns of new Array inside the Main Array loop
and push an array from another..
SecondArray = [{group: "GroupA", value: "firstfield", count: 14 },{group: "GroupA", field: "secondfield", count:23 },{group: "GroupB", field: "randomfield", count:1 }]
so the output should be
_newArray = [{
groupname: "GroupA",
columns: ["column1","column2","column3"]
col1: [{"firstfield":14, "secondfield": 23 }]
col2: "",
col3: ""
},{GroupB...}]
what I tried:
Object.keys( _newArray[0].columns).forEach( function(value, key) {
console.log(this._SecondArray[item.Group])
// push 'col + index: [Second Array]'
});
In your SecondArray the first object is having a 'value' key. I assumed it as "field"
let MainArray = {
"Data":
[{ "Group": "GroupA" }, { "Group": "GroupB" }]
}
// First push
let _newArray = [];
MainArray.Data.forEach(item => {
_newArray.push({
'groupname': item.Group,
'columns': ["column1", "column2", "column3"]
})
})
let SecondArray = [{ group: "GroupA", field: "firstfield", count: 14 }, { group: "GroupA", field: "secondfield", count: 23 }, { group: "GroupB", field: "randomfield", count: 1 }];
// Second push
_newArray.forEach(item => {
console.log(item)
let i = 1;
item.columns.forEach(cols => {
console.log(cols)
if (i == 1) {
item["col" + i] = {}
SecondArray.forEach(subItem => {
console.log(subItem)
if (subItem.group == item.groupname) {
item["col" + i][subItem.field] = subItem.count
}
})
i++
} else {
item["col" + i++] = ""
}
})
})
console.log(_newArray);
I have the following object:
data = [
{ name: 'foo', type: 'fizz', val: 9 },
{ name: 'foo', type: 'buzz', val: 3 },
{ name: 'bar', type: 'fizz', val: 4 },
{ name: 'bar', type: 'buzz', val: 7 },
];
And used lodash map:
result = _.map(data, function item, idx){
return {
key: item[key],
values: item.value,
}
}
Which results in:
[
{ key: foo, val: 9 },
{ key: foo, val: 3 },
{ key: bar, val: 4 },
{ key: bar, val: 7 },
]
but now I'm trying to return:
[
{ key: 'foo', val: 12 },
{ key: 'bar', val: 11 },
]
I tried using reduce which seems to only output to a single object, which I could then convert back into an array, but I feel like there must be an elegant way to use lodash to go from my source data straight to my desired result without all of the intermediate steps.
I thought this was addressing my exact problem, but it seems like quite a bit of work just to have to convert the object into the desired array of objects outlined above.
Cheers.
A twist to the accepted answer that uses groupBy instead of reduce to do the initial grouping:
var result = _.chain(data)
.groupBy('name')
.map((group, key) => ({ key, val : _.sumBy(group, 'val') }))
.value();
Interestingly not straight forward, because of wanting to accumulate the value by key, but then wanting the key as a value of the property key. So somewhat like an inverse map reduce:
var result =
_.chain(data)
.reduce(function(memo, obj) {
if(typeof memo[obj.name] === 'undefined') {
memo[obj.name] = 0;
}
memo[obj.name] += obj.val;
return memo;
}, {})
.map(function (val, key) {
return {key: key, val: val};
})
.value();
For the sake of brevity in es6:
_.chain(data)
.reduce((memo, obj) => {
memo[obj.name = obj.val] += obj.val;
return memo;
}, {})
.map((val, key) => ({key, val}))
.value();
You can get all the unique names using map() and uniq(), and then map() each name to get their respective sums using sumBy().
var result = _(data)
.map('name')
.uniq()
.map(key => ({
key,
val: _(data).filter({ name: key }).sumBy('val')
}))
.value();
var data = [
{ name: 'foo', type: 'fizz', val: 9 },
{ name: 'foo', type: 'buzz', val: 3 },
{ name: 'bar', type: 'fizz', val: 4 },
{ name: 'bar', type: 'buzz', val: 7 }
];
var result = _(data)
.map('name')
.uniq()
.map(key => ({
key,
val: _(data).filter({ name: key }).sumBy('val')
}))
.value();
console.log(result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.13.1/lodash.js"></script>
Here is a non es6 version:
var result = _(data)
.map('name')
.uniq()
.map(function(key) {
return {
key: key,
val: _(data).filter({ name: key }).sumBy('val')
};
})
.value();
Here's a simple non-lodash version.
const data = [{
name: 'foo',
type: 'fizz',
val: 9
},
{
name: 'foo',
type: 'buzz',
val: 3
},
{
name: 'bar',
type: 'fizz',
val: 4
},
{
name: 'bar',
type: 'buzz',
val: 7
},
]
const result = data.reduce((acc, curr) => {
const index = acc.findIndex(item => item.name === curr.name)
index > -1 ? acc[index].val += curr.val : acc.push({
name: curr.name,
val: curr.val
})
return acc
}, [])
console.log(result)