How to sort different arrays of objects inside an array

Question

How to sort separately 2 arrays of objects inside an array ? A solution with Lodash needed. Thank you.

Example of Array to sort by year:

var objects = [[{
      year: 2010,
      name: "john",
      value: 30
    },
    {
      year: 2009,
      name: "john",
      value: 40
    }
  ],
  [{
      year: 2018,
      name: "bob",
      value: 40
    },
    {
      year: 2015,
      name: "bob",
      value: 30
    }]]

Desired output after sorting by year:

[[{
      year: 2009,
      name: "john",
      value: 40
    },
    {
      year: 2010,
      name: "john",
      value: 30
    }
  ],
  [{
      year: 2015,
      name: "bob",
      value: 30
    },
    {
      year: 2018,
      name: "bob",
      value: 40
    }]]

Answer 1

orderBy on every sub collection should suffice

 var objects = [ [{ year: 2010, name: "john", value: 30 }, { year: 2009, name: "john", value: 40 }], [{ year: 2018, name: "bob", value: 40 }, { year: 2015, name: "bob", value: 30 }] ] console.log(objects.map(subObject => _.orderBy(subObject, "year"))); 

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

Answer 2

You can use map() on array of arrays and return the sorted array in map function.

 var arr = [[{year:2010,name:"john",value:30},{year:2009,name:"john",value:40}],[{year:2018,name:"bob",value:40},{year:2015,name:"bob",value:30}]]; const res = arr.map(x => x.slice().sort((a,b) => a.year - b.year)); console.log(res) 

Answer 3

You need to map the array and than sort it :

 const objects = [ [{ year: 2010, name: "john", value: 30 }, { year: 2009, name: "john", value: 40 }], [{ year: 2018, name: "bob", value: 40 }, { year: 2015, name: "bob", value: 30 }] ] const sorted = objects.map(r=>r.sort((a,b)=>a.year - b.year)); console.log(sorted) 

Answer 4

You can generate a function with _.partialRight() and _.map() to _.sortBy() the sub arrays:

 const { partialRight: pr, map, sortBy } = _; const sortSubArrays = pr(map, arr => sortBy(arr, 'year')); const objects = [[{year:2010,name:"john",value:30},{year:2009,name:"john",value:40}],[{year:2018,name:"bob",value:40},{year:2015,name:"bob",value:30}]]; const output = sortSubArrays(objects); console.log(output); 

 .as-console-wrapper { max-height: 100% !important; top: auto; } 

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

Or use lodash/fp and drop the partialRight:

 const { map, sortBy } = _; const sortSubArrays = map(sortBy('year')); const objects = [[{year:2010,name:"john",value:30},{year:2009,name:"john",value:40}],[{year:2018,name:"bob",value:40},{year:2015,name:"bob",value:30}]]; const output = sortSubArrays(objects); console.log(output); 

 .as-console-wrapper { max-height: 100% !important; top: auto; } 

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