Code to determine if the PHP array is empty

PHP judgment Array is empty preferred method: Count ($arr), size ($arr);

Copy the Code code as follows:

$arr = Array ("");
echo count ($arr);
Echo size ($arr);
Output 1

Copy the Code code as follows:

$arr = Array ();
echo count ($arr);
Echo size ($arr);
Output 0

PHP judgment Array is empty method 2:empty ($arr);

Copy the Code code as follows:

$arr = Array ("");
$result = Empty ($arr);
$result = False
$arr = Array ();
$result = Empty ($arr);
$result = True

These two methods are sufficient to deal with the question of whether simple arrays and multidimensional arrays are empty, and individuals generally use empty () to make array non-null judgments, so that the sense code looks easier to understand.

Determine if the array is empty use this function just fine count if the output is 0 then the array is empty the following is a simple test code. PHP to determine if an array is empty code

Copy the Code code as follows:

<?php
$arr = Array ();
echo count ($arr);
?>

If the output is 0, the array is empty.

PHP judgment Array is empty method 2:empty ($arr);

Copy the Code code as follows:

$arr = Array ("");
$result = Empty ($arr);
$result = False
$arr = Array ();
$result = Empty ($arr);
$result = True

PHP judgment array is empty 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?

PHP judgment array is empty two, 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:

Copy the Code code as follows:

$arr = Array (array (), array (), arr (www.jb51.net) ay ());
$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.
PHP judgment array is empty three, count ();

Copy the Code code as follows:

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

PHP judgment array is empty four, In_array (", $arr));

Copy the Code code as follows:

$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.

PHP judgment Array is empty (five);

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

Copy the Code code as follows:

$arr = Array ("", "", "");
if (empty ($arr)) echo "null";
else echo "non-null";

The result is still non-empty

PHP judgment array is empty six, with strlen (), no content as if the length is 1
We can also add a sentence print_r ($arr) to the above example;

The above is to determine whether the PHP array is empty code, including the aspects of the content, I hope the PHP tutorial interested in a friend helpful.

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