PHP to determine if an array is empty code

Determine if an array is empty code in PHP

one, for loop

The simplest and most straightforward method is to iterate through the array with a for loop. The array of known dimensions can be judged, but what if it is an unknown multidimensional array?

second, implode ();

use implode () to output the array as a string to determine if the output is empty. It seems like a good way to start at first, but as with a little bit more than two-dimensional arrays. As an example:





$arr = Array (array (), array (), array ());

$str = Implode (', ', $arr);



if (empty ($STR)) echo "null";

else echo "non-null";



It is obvious that $arr is a two-dimensional array with three empty arrays, which should also be empty, but the output is indeed non-empty. Judgment failed.

III, COUNT ();

I have to admit that the first thing I think of is this function, online also have many netizens to this when the answer, and thought has solved the problem. But take a look at the following example:



$arr = Array ("", "", "");

echo Count ($arr);



I don't think I need to say much about this method.

iv. In_array (', $arr));

not much to say, or to look at an example:



$arr = Array ("D", "s", "");

Echo In_array (', $arr);



this can only indicate that there are empty elements in the array and cannot prove that the array is empty. It's not obvious.

five, Empty ();

This Cpyeh thinks it's the same as the previous methods .



$arr = Array ("", "", "");

if (empty ($arr)) echo "null";

else echo "non-null";



The result is still non-empty



You can add a sentence print_r ($arr) to the above example;

basically Cpyeh can think of and found on the internet also above these, do not understand is on the net actually someone will mention Is_array (), probably is not very understanding of PHP, need to turn over the manual. Unfortunately, there is no way to find a perfect solution, but for general applications, the first or second should be able to meet, Cpyeh selected a convenient second. If you have questions about the above examples, please feel free to talk to each other.

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