Styjun

I have the following input Array which is dynamically generated.

let array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"]

This Array contain the Ids e.g "5c8f653a247a4d513db2468b" and it related filter e.g "5c8f653a247a4d513db2468b_Sat"

How I get the output like this

let outPut = ["id":"5c8f653a247a4d513db2468b","filter":["Mon","Thu","Wed","Sat"],"id":"5c8faea05f60dd0c9447b678","filter":["Tue","Thu","Sat"]}

using lodash or javascript

You can start coding using this code segment

var _ = require('lodash');

const array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];

const regualarData = _.filter(array, item => item.includes("_"));

const plainData = _.map(regualarData, item => 
 return 
 id: item.substring(0, item.indexOf("_")),
 day: item.substring(item.indexOf("_")+1),
 ; 
);

const nested = _.groupBy(plainData, 'id');

const response = [];
for (var key in nested) 
 if (nested.hasOwnProperty(key)) 
 response.push(id: key , filter: _.map(nested[key],t => t.day));
 


console.log(response);

You can split the string using split, and store the filter days in an object. Then use that object to create the desired format.

let array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];

//console.log( array );

// remove items with no underscore
array = array.filter( x => x.indexOf( '_' ) != -1 );

//console.log( array );

// create sortedData object
const sortedData = ;

array.forEach( function( x ) 
 const parts = x.split( '_' );
 const key = parts[0];
 const value = parts[1];
 
 if ( ! ( key in sortedData ) ) 
 sortedData[key] = [];
 
 
 sortedData[key].push( value );
 
);

//console.log( sortedData );

const output = [];
for ( let key in sortedData ) 
 if ( sortedData.hasOwnProperty( key ) ) 
 output.push( id: key, filters: sortedData[key] );
 


console.log( output );

If you use lodash, and want to take the functional approach, you need to:

• Split each item to a [id, filter] pair


• Filter out items that only have the id


• Group items by the id


• Format the objects

const flow, partialRight: pr, split, filter, groupBy, first, last, map = _;

const fn = flow(
 pr(map, item => split(item, '_')), // convert to [id, filter] pairs
 pr(filter, length: 2 ), // filter out items without filter
 pr(groupBy, first), // group by the 1st item in each pair
 pr(map, (group, id) => ( // format the objects
 id,
 filter: map(group, last) // get the filters from the pairs
 ))
)

const array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];

const result = fn(array);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

And the terser lodash/fp version:

const flow, split, filter, groupBy, first, last, map = _;

const fn = flow(
 map(split('_')), // convert to [id, filter] pairs
 filter( length: 2 ), // filters items without filter
 groupBy(first), // group by the 1st item in each pair
 map(group => ( // format the objects
 id: first(first(group)), // take the id from the first item
 filter: map(last, group) // get the filters from the pairs
 ))
)

const array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];

const result = fn(array);

console.log(result);

<script src='https://cdn.jsdelivr.net/g/lodash@4(lodash.min.js+lodash.fp.min.js)'></script>

Try this:

let array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"]
var tmpArr = [];
var tmpDay = [];
var output = [];
for(var i = 0; i < array.length; i++)
 var tmp = array[i].split("_");
 if(tmp.length == 1)
 tmpArr.push(array[i]);
 tmpDay.push([]);
 
 else 
 tmpDay[tmpArr.indexOf(tmp[0])].push(tmp[1]);
 


for(var i = 0; i < tmpArr.length; i++)
 var tmpObj = ;
 tmpObj.id = tmpArr[i];
 tmpObj.filter = tmpDay[i];
 output.push(tmpObj);


console.log(output);

Much shorter version without loadash.

var array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];
array = array.map(v => v.split('_'));
var arr = ;
array.map(ar => 
 if(arr.hasOwnProperty(ar[0]))	
 arr[ar[0]].push(ar[1]);
 else
 arr[ar[0]] = [];
 
);
var _arr = [];
for(key in arr)
 _arr.push(id:key, filter:arr[key]);

console.log(_arr);

You can make use of the lodash implicit chain sequences of collection functions and the usage of each of the collection functions' shorthand property() variations to transform this array into a properly grouped filter.

• Use invokeMap() to split each string in the array by a delimiter. In this case, we split it by _, resulting in an array of ['hash', 'day'].


• Use filter() to only get the items with a day suffix. We'll use the property shorthand variation of this collection function and evaluate the existence of day suffix which is under index 1.


• Use groupBy(), note the shorthand variation, to group each item with the hash prefix which is under index 0.


• Lastly, use map() to transform the grouped filter object into a grouped filter array by using the key (hash) of the group as the id. The resulting filter array is obtained by getting the day suffix of each of the grouped value which is under index 1 by using map(), shorthand function variation.

const result = _(array)
 .invokeMap('split', '_')
 .filter(1)
 .groupBy(0)
 .map((v, id) => ( id, filter: _.map(v, 1) ))
 .value();

const array = ["5c8f653a247a4d513db2468b", "5c8faea05f60dd0c9447b678", "5c8faea05f60dd0c9447b678_Tue", "5c8faea05f60dd0c9447b678_Thu", "5c8faea05f60dd0c9447b678_Sat", "5c8f653a247a4d513db2468b_Sat", "5c8f653a247a4d513db2468b_Wed", "5c8f653a247a4d513db2468b_Thu", "5c8f653a247a4d513db2468b_Mon"];

const result = _(array)
 .invokeMap('split', '_')
 .filter(1)
 .groupBy(0)
 .map((v, id) => ( id, filter: _.map(v, 1) ))
 .value();
 
console.log(result);

.as-console-wrappermin-height:100%;top:0!important;

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>