is there any function to get the keys of an array using javascript
Also i want to reverse and array
eg:
appz_variable['412cc16e']="ABXZ";
appz_variable['axecr6fd']="YCSET";
I want the array indexes or keys in reverse order
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1Arrays are usually indexed by integers. So what keys are you talking about? Are you talking about hashes? Please provide an example.Darin Dimitrov– Darin Dimitrov2010-11-27 11:39:05 +00:00Commented Nov 27, 2010 at 11:39
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Dupes: stackoverflow.com/questions/2980242/js-objects-and-properties, stackoverflow.com/questions/3068534/…, etcsje397– sje3972010-11-27 12:01:54 +00:00Commented Nov 27, 2010 at 12:01
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2 Answers
I assume here you're talking about an object which some label (albeit incorrectly) an "associative array". For that situation, use a for...in loop to enumerate the object, like this:
for(var key in myObject) {
if(myObject.hasOwnProperty(key)) {
alert("Key: " + key + ", Value: " + myObject[key]);
}
}
For a normal array you just loop though based on an index, like this:
for(var i=0; i<myArray.length; i++) {
alert("Position: " + i + ", Value: " + myArray[i]);
}
The second is iterating over the array, while the first is enumerating the object...you shouldn't use a for...in loop on a normal array for example, as there are many problems that can arise.
5 Comments
Anish Joseph
can u please tell me. how to. reverse an array using the first method
Anish Joseph
@Nick Craver - I just updated my question please go through it
Nick Craver
@Anish - Yeah...that order isn't guaranteed, the best you can do is loop through, you can store and presents the results backwards, but it may very by browser, so I wouldn't count on the ordering (especially in IE).
Anish Joseph
I am using php to create that array . So even if I send a reversed array from php it wont be in the same order ???
Nick Craver
@Anish - nope, not necessarily, as I said this isn't an array, it's an object.
You can index your array by numbers when it is created. perhaps like this:
appz_variable[0]['412cc16e']="ABXZ";
appz_variable[1]['axecr6fd']="YCSET";
and then you will have an "order" which you can then reverse...
