PHP uses Array_filter () function to filter empty array implementation code _php instance

Today, looking at the details of the manual query Array_filter (), I saw a small key point: If No callback is supplied, all entries of input equal to FALSE (see Converting to Boolean) would be removed. If the callback function is not given, all elements that are equal to FALSE will be removed, which is not exactly what can be used to filter an array with empty elements? Quickly write an example to test the idea:

Copy Code code as follows:

$entry = Array (

0 => ' Blue Hawaiian blog ',

1 => false,

2 => 1,

3 => NULL,

4 => ',

5 => ' http://www.jb51.net ',

6 => ' 0 ',

7 => Array (),

8 => 0

);

$validarr = Array_filter ($entry);

Print_r ($validarr);

Output results:

Array

(

[0] => Blue Hawaii Blog

[2] => 1

[5] => http://www.jb51.net

)

Some of the array elements that can be converted to Boolean false are removed and a very comprehensive filter is made to get a valid array.