CODEWITHSUNDEEP
underscore.js
user6599525
user6599525

Reputation: 285

create an array from object using underscore

I have following json as sample 

var employee=[{sex:'M',id:1},{sex:'M',id:3},{sex:'f',id:4},{sex:'f',id:5}]

I want following array 

maleIds=[1,3]
femaleIds=[4,5]

 var testFilter=_.filter(employee,function(obj) {
                return obj.sex=='M';
            });

            var testMap=_.map(testFilter, function(value, key){
                return { name : key, value : value };
            });

How can I create array from object using specific criteria ?

_filter / _map they return whole object . I want only sex value .

Upvotes: 1

Views: 892

Answers (1)

Gruff Bunny
Gruff Bunny

Reputation: 27976

First partition the employee data. This will return an array of 2 arrays; the first array contains all the males and the second the females. Then use pluck on the partitioned data to get the ids:

var employee=[{sex:'M',id:1},{sex:'M',id:3},{sex:'f',id:4},{sex:'f',id:5}]

var partitions = _.partition(employee, {sex: 'M'})

var maleIds = _.pluck(partitions[0], 'id');
var femaleIds = _.pluck(partitions[1], 'id');


	var employee=[{sex:'M',id:1},{sex:'M',id:3},{sex:'f',id:4},{sex:'f',id:5}]

	var partitions = _.partition(employee, {sex: 'M'})

	var maleIds = _.pluck(partitions[0], 'id');
	var femaleIds = _.pluck(partitions[1], 'id');

document.getElementById('males').textContent = JSON.stringify(maleIds);
document.getElementById('females').textContent = JSON.stringify(femaleIds);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

<p>
  males <pre id="males"></pre>
  females <pre id="females"></pre>
</p>

Upvotes: 1

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