I've an array with arrays of documents in it, can some help me on how to sort those arrays with multiple documents inside the array. The user can chose of the type to be searched on. If they can choose 'A' sort all the array items by value associated with type 'A', similarly for the other types. What is the best way to do this. Lodash solution would be highly beneficial. Those values can be integers/strings/guids/datetime fields.

Type is always a string, in any case I don't think it does really matter.

[
 [{type:A, value:10},{type:B, value:20},{type:C, value:15},{type:D, value:20}],
 [{type:A, value:5},{type:B, value:10},{type:C, value:35},{type:D, value:40}],
 [{type:A, value:30},{type:B, value:30},{type:C, value:25},{type:D, value:30}],
 [{type:A, value:20},{type:B, value:50},{type:C, value:55},{type:D, value:10}]
]

Desired out put if sorted by type 'A'

[[{type:A, value:5},{type:B, value:10},{type:C, value:35},{type:D, value:40}],
     [{type:A, value:10},{type:B, value:20},{type:C, value:15},{type:D, value:20}],
     [{type:A, value:20},{type:B, value:50},{type:C, value:55},{type:D, value:10}],
     [{type:A, value:30},{type:B, value:30},{type:C, value:25},{type:D, value:30}]]

I've an array with arrays of documents in it, can some help me on how to sort those arrays with multiple documents inside the array. The user can chose of the type to be searched on. If they can choose 'A' sort all the array items by value associated with type 'A', similarly for the other types. What is the best way to do this. Lodash solution would be highly beneficial. Those values can be integers/strings/guids/datetime fields.

Type is always a string, in any case I don't think it does really matter.

[
 [{type:A, value:10},{type:B, value:20},{type:C, value:15},{type:D, value:20}],
 [{type:A, value:5},{type:B, value:10},{type:C, value:35},{type:D, value:40}],
 [{type:A, value:30},{type:B, value:30},{type:C, value:25},{type:D, value:30}],
 [{type:A, value:20},{type:B, value:50},{type:C, value:55},{type:D, value:10}]
]

Desired out put if sorted by type 'A'

[[{type:A, value:5},{type:B, value:10},{type:C, value:35},{type:D, value:40}],
     [{type:A, value:10},{type:B, value:20},{type:C, value:15},{type:D, value:20}],
     [{type:A, value:20},{type:B, value:50},{type:C, value:55},{type:D, value:10}],
     [{type:A, value:30},{type:B, value:30},{type:C, value:25},{type:D, value:30}]]

• javascript
• arrays
• sorting
• lodash

• Please show the desired output – Weedoze Commented Mar 15, 2017 at 15:16
• Are A,B,C,D supposed to be strings or other objects? – Fabian Klötzl Commented Mar 15, 2017 at 15:20
• are the inner arrays always sorted by type? – Nina Scholz Commented Mar 15, 2017 at 15:38

3 Answers 3

Here's a lodash solution that uses sortBy for sorting and find to get the corresponding values with a specific type.

var result = _.sortBy(data, function(item) {
  return _.find(item, { type: 'A' }).value;
});

var data = [
  [{
    type: 'A',
    value: 10
  }, {
    type: 'B',
    value: 20
  }, {
    type: 'C',
    value: 15
  }, {
    type: 'D',
    value: 20
  }],
  [{
    type: 'A',
    value: 5
  }, {
    type: 'B',
    value: 10
  }, {
    type: 'C',
    value: 35
  }, {
    type: 'D',
    value: 40
  }],
  [{
    type: 'A',
    value: 30
  }, {
    type: 'B',
    value: 30
  }, {
    type: 'C',
    value: 25
  }, {
    type: 'D',
    value: 30
  }],
  [{
    type: 'A',
    value: 20
  }, {
    type: 'B',
    value: 50
  }, {
    type: 'C',
    value: 55
  }, {
    type: 'D',
    value: 10
  }]
];

var result = _.sortBy(data, function(item) {
  return _.find(item, { type: 'A' }).value;
});

console.log(result);

body > div { min-height: 100%; top: 0; }

<script src="https://cdnjs.cloudflare./ajax/libs/lodash.js/4.17.4/lodash.js"></script>

In plain Javascript, you could look for the given type and sort by the corresponding value.

function sort(data, type) {
    function getValue(array) {
        var value = -Number.MAX_VALUE;
        array.some(function (o) {
            if (o.type === type) {
                value = o.value;
                return true;
            }
        });
        return value;
    }

    data.sort(function (a, b) {
        var aa = getValue(a),
            bb = getValue(b);
        return isFinite(aa) && isFinite(bb) ? aa - bb : aa.localeCompare(bb);
    });
}


var data = [[{ type: 'A', value: 10 }, { type: 'B', value: 20 }, { type: 'C', value: 15 }, { type: 'D', value: 'b' }], [{ type: 'A', value: 5 }, { type: 'B', value: 10 }, { type: 'C', value: 35 }, { type: 'D', value: 'a' }], [{ type: 'A', value: 30 }, { type: 'B', value: 30 }, { type: 'C', value: 25 }, { type: 'D', value: 'd' }], [{ type: 'A', value: 20 }, { type: 'B', value: 50 }, { type: 'C', value: 55 }, { type: 'D', value: 'c' }]];

sort(data, 'A');
console.log(data);
sort(data, 'D');
console.log(data);

.as-console-wrapper { max-height: 100% !important; top: 0; }

You can dynamically create a relationship for sorting using closures.

function sortBy(key){
    return function(a,b){
        return a[key] - b[key];
    }
}

var index = {'A':0, 'B': 1, … };
var userPickedType = 'A';
yourarray.sort(sortBy(index[userPickedType]));