Php remove item in array by value

Borrowed the logic of underscore.JS _.reject and created two functions (people prefer functions!!)

array_reject_value: This function is simply rejecting the value specified (also works for PHP4,5,7)

function array_reject_value(array &$arrayToFilter, $deleteValue) {
    $filteredArray = array();

    foreach ($arrayToFilter as $key => $value) {
        if ($value !== $deleteValue) {
            $filteredArray[] = $value;
        }
    }

    return $filteredArray;
}

array_reject: This function is simply rejecting the callable method (works for PHP >=5.3)

function array_reject(array &$arrayToFilter, callable $rejectCallback) {

    $filteredArray = array();

    foreach ($arrayToFilter as $key => $value) {
        if (!$rejectCallback($value, $key)) {
            $filteredArray[] = $value;
        }
    }

    return $filteredArray;
}

So in our current example we can use the above functions as follows:

$messages = [312, 401, 1599, 3, 6];
$messages = array_reject_value($messages, 401);

or even better: (as this give us a better syntax to use like the array_filter one)

$messages = [312, 401, 1599, 3, 6];
$messages = array_reject($messages, function ($value) {
    return $value === 401;
});

The above can be used for more complicated stuff like let's say we would like to remove all the values that are greater or equal to 401 we could simply do this:

$messages = [312, 401, 1599, 3, 6];
$greaterOrEqualThan = 401;
$messages = array_reject($messages, function ($value) use $greaterOrEqualThan {
    return $value >= $greaterOrEqualThan;
});

To remove the element from an array by value, we can use the combination of array_search() and unset() functions in PHP.

Here is an example, that removes the second element "green" from the colors array by value.

<?php
$colors = array("red", "green", "yellow", "orange");

if (($key = array_search("green", $colors)) !== false) {
    unset($colors[$key]);
}

print_r($colors)
?>

Output:

Array
(
    [0] => red
    [2] => yellow
    [3] => orange
)

The unset() function doesn’t re-index the array keys, if you want to re-index it then you can use the array_values() function after unset().

<?php
$colors = array("red", "green", "yellow", "orange");

if (($key = array_search("green", $colors)) !== false) {
    unset($colors[$key]);
}

print_r(array_values($colors))
?>

Similarly, we can also use the array_diff() function like this to remove it.

$colors = array("red", "green", "yellow", "orange");

$newArray = array_diff($colors, array("green"));

print_r($newArray)

You can also use the array_diff() function to remove multiple elements by using value.

$colors = array("red", "green", "yellow", "orange");

$newArray = array_diff($colors, array("green", "yellow"));

print_r($newArray)

Note: The array_diff() function creates a new array by preserving the original array, where the first solution modifies the original array.

How do I remove a specific element from an array in PHP?

How do I remove a specific element from an array?

Which function is used to remove or delete elements from an array in PHP?

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