javascript - Pushing data to (nested) array, depending on existing object field -

i'm pushing data array within foreach-loop:

let result = []; data.foreach(function(part){     let text = part.one + part.two;     result.push({          text: text,          element: [{ id: part._id, page: part.page }]     }); }); 

but need check if text in object of array.

if there such object, page part.page should added array of object identical text field. otherwise data should added result array.

example

result = [     {         text: 'some text',         element: [{ id: 1, page: '12-34'}]     } ] 

if next part-elements this:

{ id: 2, one: 'some ', two: 'text', page: '45-67' } { id: 3, one: 'another  ', two: 'text', page: '12-34' } 

result should get

result = [     {         text: 'some text',         pages: [{ id: 1, page: '12-34'}, { id: 2, page: '45-67' }] // page added array, text identical     },     {         text: 'another text',         pages: [{ id: 3, page: '12-34'}]     } ] 

additional question

is possible sort result array first text-field , second element-objects page-field?

this wrong order first object:

[{ id: 2, page: '45-67'}, { id: 1, page: '12-34' }] 

...and 'another text' should before 'some text'

you can use find check if element exists. in case use findindex updating nested array:

let index = result.findindex(x => x.reference === reference);  if (index === -1) {     result.push({          text: text,         element: [             {                  id: part._id,                  page: part.page              }         ]     }); } else {     result[index].element.push(         {              id: part._id,              page: part.page          }     ); }