CODEWITHSUNDEEP
javascript
mgig
mgig

Reputation: 2915

How do I find unique values in a list of javascript objects over multiple keys?

I have an array of javascript objects. Here is an example:

[{'first': 'Mary', 'last':'Smith', 'task':'managing'},
{'first': 'Mary', 'last':'Smith', 'task':'research'},
{'first': 'Henry', 'last':'Ford', 'task':'assembling'},
{'first':'Henry', 'last':'Winkler', 'task':'acting;}]

and I want to find all elements in the array that are distinct in first AND last name. The output I'm looking for is of the form:

[{'first': 'Mary', 'last':'Smith'},
 {'first': 'Henry', 'last':'Ford'},
 {'first': 'Henry', 'last':'Winkler'}]

How do I do this in javascript?

Upvotes: 2

Views: 62

Answers (3)

Sashi
Sashi

Reputation: 145

@Minusfour You are just ahead of me. I got same solution.

array.forEach( function (arrayItem)
{
   if(hashMap[arrayItem.first + arrayItem.last] == 0){
     hashMap[arrayItem.first + arrayItem.last] = 1;
     finalArray.push(arrayItem);
   }
});

Upvotes: 0

Simon H
Simon H

Reputation: 21005

This would be a good time to roll out the new ES6 set

var s = new Set();
arr.forEach(a => s.add({'first':a.first, 'last': a.last}))
var myArr = Array.from(s);

Upvotes: 1

MinusFour
MinusFour

Reputation: 14423

I would use a Map for this:

var m = new Map();
arr.forEach(function(obj){
    var name = obj.first + ' ' + obj.last;
    if(!m.has(name)){
       m.set(name, { first : obj.first, last : obj.last});
    }
});
var uniques = Array.from(m.values());

Upvotes: 2

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