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Javascript isArray() : Check if an element/object is an Array

Submitted by DerGrobe on Thu, 04/16/2009 - 11:02

I work on the front-end part of Zero RRD framework again. It was a very basic interface and the usability wasn't, well isn't that good.

The new stuff is mostly JavaScript and I needed to check if a variable is an array or not. I found the snippet at bram.us, but it isn't fully working for me.

The problem is with variables that are null in that case you'll run into an error. The slightly improved version takes that into account.

  1. function isArray(obj) {
  2.     if (obj == null) return false;
  3.     return obj.constructor == Array;
  4. }

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#1Submitted by Canon printer driver - Canon driver - 4300 bjc canon driver (not verified) on Wed, 08/25/2010 - 13:40.

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[...] Javascript isArray() : Check if an element/object is an Array 16 Apr 2009. Free DNS EveryDNS.net and Bind 9 setup. 04/05/2010 - 07:19. Updated Debian Lenny eAccelerator packages again (AMD64). 3 weeks 6 hours ago; Pingback. I work on the front-end part of Zero RRD framework again. Javascript isArray() : Check if an element/object is an Array [...]

#2Submitted by Web site of the state - State web - Virginia state governmen (not verified) on Thu, 08/19/2010 - 23:20.

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[...] Javascript isArray() : Check if an element/object is an Array 16 Apr 2009. Free DNS EveryDNS.net and Bind 9 setup. 04/05/2010 - 07:19. Updated Debian Lenny eAccelerator packages again (AMD64). 3 weeks 6 hours ago; Pingback. I work on the front-end part of Zero RRD framework again. Javascript isArray() : Check if an element/object is an Array [...]

#3Submitted by Seb (not verified) on Wed, 10/07/2009 - 14:25.

...

The constructor property of the Array object can be overwritten.
better:

  1. var isArray = function(obj) {
  2.     return toString.apply( obj ) === toString.apply( [] );
  3. }

#4Submitted by vurentjie (not verified) on Tue, 12/15/2009 - 13:25.

not entirely sure here but

not entirely sure here but why is....

  1. return obj instanceof Array;

not used?

btw the captcha's are incredibly noisy - difficult to decipher