The specific way to determine if an array is empty in PHP_PHP Tutorial

LearningPHP determines whether an array is empty, for loop

The simplest and most direct method is to use a for loop to traverse the array. It can be judged for arrays with known dimensions, but what should we do if it is an unknown multi-dimensional array?

PHP determines whether the array is empty, implode();

Use implode() to output the array as a string, and determine whether the output string is empty. At first glance, it seems to be a good method, but unfortunately, like the previous point, it does not work for arrays with more than two dimensions. For example:

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

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

if(empty ($str)) echo "empty";

else echo "not empty";

Obviously $arr is a two-dimensional array containing three empty arrays. It should be considered empty, but the output is indeed Right or wrong. Judgment failed.

PHP determines that the array is empty, count();

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

echo count($arr );

PHP determines that the array is empty, in_array('', $arr));

$arr= array("d","s","" );

echo in_array('', $arr);

This can only show that there are empty elements in the array, but cannot prove that the array is empty. Obviously not.

PHP determines that the array is empty, empty();

This cpyeh feels similar to the previous methods

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

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

else echo "not empty";

The result is still non-empty

PHP determines that the array is Empty 6. Use strlen(). If there is no content, the length seems to be 1

We can also add print_r($arr); to the above example to see.

http://www.bkjia.com/PHPjc/446357.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/446357.htmlTechArticleWhen learning PHP, the simplest and most direct way to determine whether an array is empty or a for loop is to use a for loop. Traverse the array. It can be judged for arrays with known dimensions, but if it is an unknown number...