Get single object from array using JavaScript functions

Question

I have this array of objects:

var frequencies = [{id:124,name:'qqq'}, 
                  {id:589,name:'www'}, 
                  {id:45,name:'eee'},
                  {id:567,name:'rrr'}];

I need to get an object from the array above by the id value.

For example I need to get the object with id = 45.

I tried this:

var t = frequencies.map(function (obj) { return obj.id==45; });

But I didn't get the desired object.

How can I implement it using JavaScript prototype functions?

score 24 · Answer 1 · answered Jul 20 '16 at 12:56

24

If your id's are unique you can use find()

var frequencies = [{"id":124,"name":"qqq"},{"id":589,"name":"www"},{"id":45,"name":"eee"},{"id":567,"name":"rrr"}];
                  
var result = frequencies.find(function(e) {
  return e.id == 45;
});

console.log(result)

answered Jul 20 '16 at 12:56

Nenad Vracar

111,264
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Great! `find()` is perfect as it only returns a single entry from an array :-) – Philipp May 24 '19 at 10:07

Satpal · Accepted Answer · 2016-07-20T13:16:28.007

19

You need filter() not map()

var t = frequencies.filter(function (obj) { 
    return obj.id==45; 
})[0];

edited Jul 20 '16 at 13:16

answered Jul 20 '16 at 12:54

Satpal

129,808
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Is filter method works in InternetExplorer? – Michael Jul 20 '16 at 12:57
@Michael: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter#Browser_compatibility . – Felix Kling Jul 20 '16 at 12:58
3

Filter method return array(a single object array), any idea how can return object not array? – Michael Jul 20 '16 at 13:14

Get single object from array using JavaScript functions

2 Answers2