Accessing key in an Array using JavaScript

Question

RaceArray: [{
    Unknown: 0,
    Caucasian: 1,
    AfricanAmerican: 2,
    AmericanIndian: 3,
    Asian: 4,
    Hispanic: 5,
    Other: 6
 }]

How can i access the key's alone in my JavaScript and form it as an separate array.

Desired outcome...

RaceArray = ['Unknown','Caucasian']

I'm not 100% sure what you're asking. You've posted the before, maybe post the after (desired outcome)? — Brad Christie
– Brad Christie, Commented Jun 10, 2011 at 14:57
Apart from the (not very good) coding question my advise would be to study the concept of race first. Start @ en.wikipedia.org/wiki/Race_(classification_of_humans) — KooiInc
– KooiInc, Commented Jun 10, 2011 at 15:50

gen_Eric · Accepted Answer · 2011-06-10 15:00:29Z

5

var RaceObj = [{
    Unknown: 0,
    Caucasian: 1,
    AfricanAmerican: 2,
    AmericanIndian: 3,
    Asian: 4,
    Hispanic: 5,
    Other: 6
}];

var obj = RaceObj[0], Keys = [];
for(var key in obj){
  if(obj.hasOwnProperty(key)){
    Keys.push(key);
  }
}

answered Jun 10, 2011 at 15:00

gen_Eric

228k42 gold badges304 silver badges343 bronze badges

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

2 Comments

John Cooper Over a year ago

what is RaceObj[0] here... why do we use it.

gen_Eric Over a year ago

@John: In your RaceArray, you have an array containing 1 element, an object. So, RaceObj[0] gets that object. I also renamed RaceArray to RaceObj.

John Kalberer · Accepted Answer · 2011-06-10 14:58:11Z

-1

There may be a simpler solution but you can do:

var keys = [];
for(var key in RaceObj) {
    if (RaceObj.hasOwnProperty(key)) {
        keys.push(key);
    }
}

answered Jun 10, 2011 at 14:58

John Kalberer

5,8001 gold badge25 silver badges27 bronze badges

5 Comments

Brad Christie Over a year ago

Note that RaceObj is an array first and an object second. You'll need to iterate the array before retrieving the keys.

Rizwan Sharif Over a year ago

aham i will recommend not to use for (var key in obj) .. instead use jquery's $.each or put if condition checking if the property belongs to object and not its prototype

Gumbo Over a year ago

You should use hasOwnProperty to only get own properties.

Brad Christie Over a year ago

@RizwanSharif: Why involve a jQuery object in this? Are you aware .each() uses for(... in ...) already?

Austin Hyde Over a year ago

When iterating over objects like this, you always need to use a hasOwnProperty check, otherwise properties that exist on the prototype will be iterated over as well, which is usually not expected behavior.

Collectives™ on Stack Overflow

Accessing key in an Array using JavaScript

2 Answers 2

2 Comments

5 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related