Comments on: Checking for the presence of the arrays in PHP http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235 Wed, 15 Sep 2010 22:35:31 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Sid http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235/comment-page-1#comment-174943 Sid Fri, 23 Mar 2007 15:15:18 +0000 http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235#comment-174943 I hate to burst your bubble but is_array is faster. Looking at your code you could have used microtime (with the parameter set to true), better yet you should have used PEAR's Benchmark. I did and comparing isset($array[0]) to is_array came up with: Below results where when the function were checking the integer 123. Mean execution time for is_array: 0.000121051421165 Mean execution time for isset: 0.000126702299118 Below results where when the function were checking the array (1,2,3) Mean execution time for is_array: 0.000145638279915 Mean execution time for isset: 0.000153319172859 Also note that the count() function does <strong>not actually count the number of elements. If you look at the struct for a PHP variable (the same for all data types) it's simple an attribute that count reads which gets changed whenever the arrays length ever changes. Considering is_array is easier to read, catches more "edge" cases (if they can be called that) and it slightly quick I'd say that's what should be used. Dixon: empty could simply return the wrong information and it's actually the same speed as is_array anyway,</strong> I hate to burst your bubble but is_array is faster. Looking at your code you could have used microtime (with the parameter set to true), better yet you should have used PEAR’s Benchmark. I did and comparing isset($array[0]) to is_array came up with:

Below results where when the function were checking the integer 123.
Mean execution time for is_array: 0.000121051421165
Mean execution time for isset: 0.000126702299118
Below results where when the function were checking the array (1,2,3)
Mean execution time for is_array: 0.000145638279915
Mean execution time for isset: 0.000153319172859

Also note that the count() function does not actually count the number of elements. If you look at the struct for a PHP variable (the same for all data types) it’s simple an attribute that count reads which gets changed whenever the arrays length ever changes.

Considering is_array is easier to read, catches more “edge” cases (if they can be called that) and it slightly quick I’d say that’s what should be used.

Dixon: empty could simply return the wrong information and it’s actually the same speed as is_array anyway,

]]> By: Dixon http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235/comment-page-1#comment-161770 Dixon Wed, 07 Mar 2007 22:52:21 +0000 http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235#comment-161770 Sorry for lifting this post up... But how abaout empty() ??? Sorry for lifting this post up… But how abaout empty() ???

]]> By: Adam Trachtenberg http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235/comment-page-1#comment-110411 Adam Trachtenberg Mon, 25 Sep 2006 21:19:20 +0000 http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235#comment-110411 You should be careful with this syntax, as this will cause problems when $array is a string because $a[0] will be set to the first character of the string. Personally, I find is_array() to be far and away the most clearly named of all the PHP functions you can use to test is a variable is an array, so I always use that regardless of any minimal speed benefit another function may have. You should be careful with this syntax, as this will cause problems when $array is a string because $a[0] will be set to the first character of the string.

Personally, I find is_array() to be far and away the most clearly named of all the PHP functions you can use to test is a variable is an array, so I always use that regardless of any minimal speed benefit another function may have.

]]> By: Alex http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235/comment-page-1#comment-109710 Alex Sat, 23 Sep 2006 00:17:09 +0000 http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235#comment-109710 Ok, I stand corrected, if (isset($array[0])) is the fastest option and it accounts for $array[0] being equal to zero. Ok, I stand corrected, if (isset($array[0])) is the fastest option and it accounts for $array[0] being equal to zero.

]]> By: Sergey Chernyshev http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235/comment-page-1#comment-109640 Sergey Chernyshev Fri, 22 Sep 2006 20:26:46 +0000 http://www.moskalyuk.com/blog/checking-for-the-presence-of-the-arrays-in-php/1235#comment-109640 You assume that if there is no 0th element then array is empty. Is it correct assumption? I thought that PHP's arrays are associative arrays and there can be $array['abc'] but not $array[0]. In any case, your solution might be much better if you know that array is not associative. Also, what will happen in your code if $array1[0] equals 0 - will it return true or false? You assume that if there is no 0th element then array is empty. Is it correct assumption?

I thought that PHP’s arrays are associative arrays and there can be $array['abc'] but not $array[0].

In any case, your solution might be much better if you know that array is not associative.

Also, what will happen in your code if $array1[0] equals 0 – will it return true or false?

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