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how to fetch array keys with jQuery?
php built-in function array_keys(), equivalent in jquery
is there any built in function in jquery similar to that of php array_keys(),.
please suggest
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1Check this out: stackoverflow.com/questions/1254227/…Josh– Josh2012-10-09 14:34:34 +00:00Commented Oct 9, 2012 at 14:34
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1Btw: Arrays in Javascript can only have numerical keys, there's no such thing as an associative array. It only can be simulated by an object (but has flaws)dan-lee– dan-lee2012-10-09 14:39:04 +00:00Commented Oct 9, 2012 at 14:39
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5 Answers
You will have to define your own function to get the same functionality. Try this:
function arrayKeys(input) {
var output = new Array();
var counter = 0;
for (i in input) {
output[counter++] = i;
}
return output;
}
arrayKeys({"one":1, "two":2, "three":3}); // returns ["one","two","three"]
Comments
No there isn't anything specific in jQuery for this. There is a javascript method but it is not widely supported yet Object.keys() so people don't use it for generic projects. Best thing i could think of is
var keys = $.map(your_object, function(value, key) {
return key;
});
1 Comment
sMyles
This is the best answer, but
Object.keys() is widely supported now, including IE9+ developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…You don't need jQuery or any other library for this -- it's a standard part of Javascript.
for(var key in myObject) {
alert(key);
}
That should be sufficient for you to loop through the object. But if you want to actually get the keys into their own array (ie turn it into a genuine clone of the php function), then it's fairly trivial to extend the above:
function array_keys(myObject) {
output = [];
for(var key in myObject) {
output.push(key);
}
return output;
}
Note, there are caveats with using the for(..in..) technique for objects that have properties or methods that you don't want to include (eg core system properties), but for a simple object that you've created yourself or from a JSON string, it's ideal.
(For more info on the caveats, see http://yuiblog.com/blog/2006/09/26/for-in-intrigue/)
Comments
Take a look at PHPJS, a project that aims to reproduce many PHP functions in vanilla JavaScript with minimal dependencies. In your case, you want array_keys.
answered Oct 9, 2012 at 14:36
Niet the Dark Absol
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Comments
In JavaScript there's no such thing like associative arrays. Objects (object literals) handle similar cases.
var keys = [], i = 0;
for( keys[ i++ ] in yourObject );
And now keys contains all yourObject property names (keys).
