Filter JavaScript Object by value

Question

I have this object array:

var result = [
{
    appAddress:"127.0.0.1",
    name:"AppServer1",
    dbConnection:""
},
{
    appAdress:"",
    name:"DBServer1",
    dbConnection:"Server=.;Database=master;Integrated Security=SSPI"
}];

Now i need to get only the name values (into an array), where the appAddress isn't empty. I tried array.filter() and $.map() but none of these methods seems to do what i want.

This is what i tried:

var appServers = $.map(result, function (val, key) {
    return (key == 'appAddress' && val.length > 0) ? key : null;
    });

and

var appServers = result.filter(function (entry) {
    return entry['displayName'];
    });

Show what you have tried. And this is quite a simple task to do yourself. Just loop the array, check the appAddress, if it's NOT empty, push it on to a new array that contains the results. — musefan
– musefan, Commented Jul 22, 2015 at 14:25
What did you try? What happened? .filter() and .map() are exactly what you need. — SLaks
– SLaks, Commented Jul 22, 2015 at 14:25
Thanks for showing what you've tried. Your problem with your use of $map is that you expect it to iterate over the properties of each object, but it does not: it iterates over the array. key will never be "appAddress", because $.map is operating on an array (which only has key names like 0, 1, 2, etc..), not the objects inside that array. As shown in Matthias's answer, you should use the first argument (val) to access each object and val.appAddress/val.name to get its property values. — apsillers
– apsillers, Commented Jul 22, 2015 at 14:34

musefan · Accepted Answer · 2015-07-22 14:35:11Z

2

First off, your object definitions are wrong. You need to use : instead of =.

Next, you can do this with a simple for loop:

var output = [];
for (var i = 0; i < result.length; i++) {
    var item = result[i];
    if (item.appAddress) output.push(item.name);
}

Here is a working example

answered Jul 22, 2015 at 14:35

musefan

48.5k21 gold badges144 silver badges193 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

jad-panda · Accepted Answer · 2015-07-22 14:50:00Z

1

For filtering you can use filter and map methods of Array. See the below example.

Array.prototype.filter Docs

Array.prototype.map Docs

var result = [{
  appAdress: "127.0.0.1",
  name: "AppServer1",
  dbConnection: ""
}, {
  appAdress: "",
  name: "DBServer1",
  dbConnection: "Server=.;Database=master;Integrated Security=SSPI"
}];


// First Solution
var out = result.filter(function(obj) {
  return obj.appAdress;
}).map(function(obj) {
  return obj.name;
})

// Second Solution
var namesArr = [];
result.forEach(function(obj) {
  if (obj.appAdress) {
    namesArr.push(obj.name);
  }
});



document.querySelector('#out').innerHTML = JSON.stringify(out, undefined, 4);
document.querySelector('#out2').innerHTML = JSON.stringify(namesArr, undefined, 4);

First Solution
<pre id="out"></pre>

<hr/>

Second Solution
<pre id="out2"></pre>

edited Jul 22, 2015 at 14:50

answered Jul 22, 2015 at 14:36

jad-panda

2,54717 silver badges22 bronze badges

2 Comments

jad-panda Over a year ago

@musefan see the updated implementation. i have added map after filter.

Daniel Over a year ago

This (first Solution) worked for me. First i need to filter and then map exposes the single object value. Thanks!

HaloWebMaster · Accepted Answer · 2015-07-22 19:50:16Z

1

One thing you could probably do is

var names = result.filter(
    function (t) {
        return t.appAddress != "";
}).map(
    function (t) {
        return t.name;
});

edited Jul 22, 2015 at 19:50

answered Jul 22, 2015 at 14:25

HaloWebMaster

9286 silver badges16 bronze badges

2 Comments

HaloWebMaster Over a year ago

Missed that part of the question X.X updated my answer.

musefan Over a year ago

Better to format your answer as code (4 spaces), rather that quote ( > )

marianc · Accepted Answer · 2015-07-23 22:31:12Z

1

You can use reduce like this:

var result = [
    {
        appAdress: "127.0.0.1",
        name: "AppServer1",
        dbConnection: ""
    },
    {
        appAdress: "",
        name: "DBServer1",
        dbConnection: "Server=.;Database=master;Integrated Security=SSPI"
    }];

var addresses = result.reduce(function (acc, it) {
    if (it.appAdress) {
        acc.push(it.name);
    }
    return acc;
}, []);

console.log(addresses);

Please check the result in console.

edited Jul 23, 2015 at 22:31

answered Jul 22, 2015 at 14:33

marianc

4491 gold badge4 silver badges13 bronze badges

1 Comment

epascarello Over a year ago

I keep forgetting about reduce +1

Matthias A. Eckhart · Accepted Answer · 2015-07-22 14:59:37Z

0

The objects defined in your result array are not valid. Object values are written as name:value pairs (separated by a colon).

Try this:

var result = [{
  appAdress: "127.0.0.1",
  name: "AppServer1",
  dbConnection: ""
}, {
  appAdress: "",
  name: "DBServer1",
  dbConnection: "Server=.;Database=master;Integrated Security=SSPI"
}];

var resultArr = $.map(result, function(val, i) {
  if (val.appAdress.length > 0) return val.name;
});

console.log(resultArr);

  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Run on JSFiddle or read more about jQuery.map().

edited Jul 22, 2015 at 14:59

answered Jul 22, 2015 at 14:26

Matthias A. Eckhart

5,1544 gold badges30 silver badges36 bronze badges

Collectives™ on Stack Overflow

Filter JavaScript Object by value

5 Answers 5

Comments

2 Comments

2 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

2 Comments

2 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related