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Remove empty array elements


Question

Some elements in my array are empty strings based on what the user has submitted. I need to remove those elements. I have this:

foreach($linksArray as $link)
{
    if($link == '')
    {
        unset($link);
    }
}
print_r($linksArray);

But it doesn't work. $linksArray still has empty elements. I have also tried doing it with the empty() function, but the outcome is the same.

2019/07/06
1
806
7/6/2019 7:43:44 PM

Accepted Answer

As you're dealing with an array of strings, you can simply use array_filter(), which conveniently handles all this for you:

print_r(array_filter($linksArray));

Keep in mind that if no callback is supplied, all entries of array equal to FALSE (see converting to boolean) will be removed. So if you need to preserve elements that are i.e. exact string '0', you will need a custom callback:

// PHP 7.4 and later
print_r(array_filter($linksArray, fn($value) => !is_null($value) && $value !== ''));

// PHP 5.3 and later
print_r(array_filter($linksArray, function($value) { return !is_null($value) && $value !== ''; }));

// PHP < 5.3
print_r(array_filter($linksArray, create_function('$value', 'return $value !== "";')));
2020/03/10
1583
3/10/2020 3:20:27 AM

You can use array_filter to remove empty elements:

$emptyRemoved = array_filter($linksArray);

If you have (int) 0 in your array, you may use the following:

$emptyRemoved = remove_empty($linksArray);

function remove_empty($array) {
  return array_filter($array, '_remove_empty_internal');
}

function _remove_empty_internal($value) {
  return !empty($value) || $value === 0;
}

EDIT: Maybe your elements are not empty per se but contain one or more spaces... You can use the following before using array_filter

$trimmedArray = array_map('trim', $linksArray);
2016/02/10

The most popular answer on this topic is absolutely INCORRECT.

Consider the following PHP script:

<?php
$arr = array('1', '', '2', '3', '0');
// Incorrect:
print_r(array_filter($arr));
// Correct:
print_r(array_filter($arr, 'strlen'));

Why is this? Because a string containing a single '0' character also evaluates to boolean false, so even though it's not an empty string, it will still get filtered. That would be a bug.

Passing the built-in strlen function as the filtering function will work, because it returns a non-zero integer for a non-empty string, and a zero integer for an empty string. Non-zero integers always evaluate to true when converted to boolean, while zero integers always evaluate to false when converted to boolean.

So, the absolute, definitive, correct answer is:

$arr = array_filter($arr, 'strlen');
2016/06/28

$linksArray = array_filter($linksArray);

"If no callback is supplied, all entries of input equal to FALSE will be removed." -- http://php.net/manual/en/function.array-filter.php

2010/09/06

    $myarray = array_filter($myarray, 'strlen');  //removes null values but leaves "0"
    $myarray = array_filter($myarray);            //removes all null values
2012/04/22

You can just do

array_filter($array)

array_filter: "If no callback is supplied, all entries of input equal to FALSE will be removed." This means that elements with values NULL, 0, '0', '', FALSE, array() will be removed too.

The other option is doing

array_diff($array, array(''))

which will remove elements with values NULL, '' and FALSE.

Hope this helps :)

UPDATE

Here is an example.

$a = array(0, '0', NULL, FALSE, '', array());

var_dump(array_filter($a));
// array()

var_dump(array_diff($a, array(0))) // 0 / '0'
// array(NULL, FALSE, '', array());

var_dump(array_diff($a, array(NULL))) // NULL / FALSE / ''
// array(0, '0', array())

To sum up:

  • 0 or '0' will remove 0 and '0'
  • NULL, FALSE or '' will remove NULL, FALSE and ''
2015/02/16

Source: https://stackoverflow.com/questions/3654295
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