how to fetch array keys with jQuery?

Question

Good afternoon. I have an array with some keys, and values in them. I then need to fetch the array keys and not the data in them. I want to do this with jQuery. I know for example that PHP has a function called array_keys(); which takes the array as a parameter and gives you an array back with each key in each index.

This is what I came up with, and it works... the only problem is that it seems so unefficent;

var foo = []; foo['alfa'] = "first item"; foo['beta'] = "second item";  for (var key in foo) {     console.log(key); } 

This will output;

alfa beta 

But is there any predefined function for this, as in PHP or any other more effective way of getting this?

Answer 1

you can use the each function:

var a = {}; a['alfa'] = 0; a['beta'] = 1; $.each(a, function(key, value) {       alert(key) }); 

it has several nice shortcuts/tricks: check the gory details here

Answer 2

Using jQuery, easiest way to get array of keys from object is following:

$.map(obj, function(element,index) {return index}) 

In your case, it will return this array: ["alfa", "beta"]