How to collect all array unique values from array of objects using underscore?

Question

I have an array of objects. Like

    project=[
        {
            name : "A"
            dept : ["a", "b", "c"]
        },
        {
            name : "B"
            dept : ["a", "e", "f", "g"]
        },
        {
            name : "C"
            dept : ["b", "c", "e", "j"]
        },
    ]

Now I want to collect all unique array values of dept from this array of object using underscore. The output should be save in a new array. Like

var newArray = ["a", "b", "c", "e", "f", "g", "j"]

I am new in underscore.js. Thanks in advance.

You can flatten the all arrays dept and get the _uniq

jean Pokou
– jean Pokou

2016-10-21 12:17:41 +00:00
Commented Oct 21, 2016 at 12:17 — jean Pokou
– jean Pokou, Commented Oct 21, 2016 at 12:17

Thalaivar · Accepted Answer · 2016-10-21 12:22:37Z

1

var project = [{
    name: "A",
    dept: ["a", "b", "c"]
}, {
    name: "B",
    dept: ["a", "e", "f", "g"]
}, {
    name: "C",
    dept: ["b", "c", "e", "j"]
}, ]



_UNIQUEAGEARRAY = _.flatten(project.map(function(item) {
    return item.dept
}));

console.log(_.uniq(_UNIQUEAGEARRAY));

document.body.innerHTML = JSON.stringify(_UNIQUEAGEARRAY);

A Fiddle:

http://jsfiddle.net/7k3ewb49/

answered Oct 21, 2016 at 12:22

Thalaivar

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1 Comment

Anudeep Over a year ago

Goodness. Exactly what I want. Thanks a lot Thalaivar.

Cristian Lupascu · Accepted Answer · 2016-10-21 12:17:15Z

1

This should do it:

_.uniq(_.flatten(project.map(x => x.dept)));

answered Oct 21, 2016 at 12:17

Cristian Lupascu

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Comments

Nenad Vracar · Accepted Answer · 2016-10-21 12:20:28Z

1

You can use Set and reduce() to do this in pure js.

var project = [{
  name: "A",
  dept: ["a", "b", "c"]
}, {
  name: "B",
  dept: ["a", "e", "f", "g"]
}, {
  name: "C",
  dept: ["b", "c", "e", "j"]
}];

var result = [...new Set(project.reduce((r, e) => r.concat(e.dept), []))]
console.log(result)

answered Oct 21, 2016 at 12:20

Nenad Vracar

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Comments

Gruff Bunny · Accepted Answer · 2016-10-21 12:23:18Z

Here's a solution using underscore's pluck, flatten and uniq:

var result = _.chain(project)
    .pluck('dept')
    .flatten()
    .uniq()
    .value();

	  var  project=[
        {
            name : "A",
            dept : ["a", "b", "c"]
        },
        {
            name : "B",
            dept : ["a", "e", "f", "g"]
        },
        {
            name : "C",
            dept : ["b", "c", "e", "j"]
        },
    ]

    var result = _.chain(project)
    	.pluck('dept')
    	.flatten()
    	.uniq()
    	.value();
        
document.getElementById('result').textContent = JSON.stringify(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

<p>
  <pre id="result"></pre>
</p>

Dhruv · Accepted Answer · 2016-10-21 12:26:01Z

0

Try This.

var projects = [{
  name: "A",
  dept: ["a", "b", "c"]
}, {
  name: "B",
  dept: ["a", "e", "f", "g"]
}, {
  name: "C",
  dept: ["b", "c", "e", "j"]
}]

var depts = [];

projects.map((project) => {
  depts = depts.concat(project.dept)
});

var result = depts.filter((item, pos) => depts.indexOf(item) == pos);

console.log(result);

answered Oct 21, 2016 at 12:26

Dhruv

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Comments

Maxx · Accepted Answer · 2016-10-21 12:30:54Z

0

ES2015 version:

const newArray = project.reduce((res, {dept}) => 
    (dept.forEach(v => !res.some(r => r === v) && res.push(v)), res), []);

also

const newArray = [...new Set(Array.prototype.concat.apply([], project.map(({dept}) => dept)))]

edited Oct 21, 2016 at 12:30

answered Oct 21, 2016 at 12:21

Maxx

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Comments

Nina Scholz · Accepted Answer · 2016-10-21 12:49:58Z

0

You could use spread syntax ... and Set

var project = [{ name: "A", dept: ["a", "b", "c"] }, { name: "B", dept: ["a", "e", "f", "g"] }, { name: "C", dept: ["b", "c", "e", "j"] }];

var result = project.reduce((r, a) => [...new Set([...r, ...a.dept])], []);
console.log(result);

answered Oct 21, 2016 at 12:49

Nina Scholz

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