Getting objects from array with a certain property

Question

Have some data:

[
 {
   property1: 1,
   property2: 2,     
 },
 {
   property1: 1,
   property2: 3,     
 },
 {
   property1: 2,
   property2: 3,     
 }
]

I need to get all objects of this array where property1=1. Is there more easier or shorter way to do this than something like:

 for(var i=0;i<array.length;i++){
   if(array[i]["property1"]==1) ....//some action
 }

Like in jquery I can use selector for DOM elements, if I need to get all span's with property1=1 I use $("span[property1=1]").each....

I don't have any clue why this is getting downvoted. OP clearly shown his efforts. — Suresh Atta, Jul 20 '17 at 17:00

adeneo · Accepted Answer · 2017-07-20T16:59:31.143

2

You can just filter the array with Array.filter based on the property property1

var arr = [
   { property1: 1, property2: 2 },
   { property1: 1, property2: 3 },
   { property1: 2, property2: 3 }
];

var res = arr.filter( x => x.property1 === 1);

console.log(res)

Array.filter() calls a provided callback function once for each element in an array, and constructs a new array of all the values for which callback returns a value that coerces to true.

Array elements which do not pass the callback test are simply skipped, and are not included in the new array.

edited Jul 20 '17 at 16:59

answered Jul 20 '17 at 16:53

adeneo

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It would be a lot more helpful than just saying 'filter it' if you would explain. – Andrew Li Jul 20 '17 at 16:54
1

@AndrewLi - There's not much to explain, it's one line that filters based on a property? – adeneo Jul 20 '17 at 16:55
2

Say 'it filter based on the result of calling the callback on each element of the array' and how the return value is a boolean on whether it's kept... there are just too many code-dump posts in the JS tag – Andrew Li Jul 20 '17 at 16:56
2

@AndrewLi - If you think I'm not explaining it well enough, post your own answer. – adeneo Jul 20 '17 at 16:57

score 1 · Answer 2 · edited Jul 20 '17 at 18:38

1

You can loop the array as you are doing right now. All you need to do is to create a new array and to push the found objects to that array.

However, there is array's filter() function:

The filter() method creates a new array with all elements that pass the test implemented by the provided function.

var filteredArray = array.filter(function(obj){
   return obj.property1 === 1;
})

edited Jul 20 '17 at 18:38

Boghyon Hoffmann

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answered Jul 20 '17 at 16:53

Suresh Atta

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score -4 · Answer 3 · edited Jul 21 '17 at 05:10

-4

kicked out this: Why not use lodash? like:

 _.filter(arr, {property1: 1})

use arr.filter(o => { return o.property1 === 1; })

edited Jul 21 '17 at 05:10

4b0

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answered Jul 20 '17 at 16:54

Shuming Liu

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Lodash isn't tagged, so don't include it in an answer. No need for it in an operation like this. – Andrew Li Jul 20 '17 at 16:55
2

Hardly merits a whole library for such a simple task – charlietfl Jul 20 '17 at 16:55
1

use an entire library when JS can do this natively? -_-a – JJJ Jul 20 '17 at 16:56
oops, first time to answer question... So, use arr.filter(o => { return o.property1 === 1; }) – Shuming Liu Jul 20 '17 at 17:03

Getting objects from array with a certain property

3 Answers3