PHP Array Delete by Value (Not Key)

PHP array delete by value (not key)

Using array_search() and unset, try the following:

if (($key = array_search($del_val, $messages)) !== false) {
    unset($messages[$key]);
}

array_search() returns the key of the element it finds, which can be used to remove that element from the original array using unset(). It will return FALSE on failure, however it can return a false-y value on success (your key may be 0 for example), which is why the strict comparison !== operator is used.

The if() statement will check whether array_search() returned a value, and will only perform an action if it did.

Removing array item by value

How about:

if (($key = array_search($id, $items)) !== false) unset($items[$key]);

or for multiple values:

while(($key = array_search($id, $items)) !== false) {
    unset($items[$key]);
}

This would prevent key loss as well, which is a side effect of array_flip().

PHP: How to remove specific element from an array?

Use array_search to get the key and remove it with unset if found:

if (($key = array_search('strawberry', $array)) !== false) {
    unset($array[$key]);
}

array_search returns false (null until PHP 4.2.0) if no item has been found.

And if there can be multiple items with the same value, you can use array_keys to get the keys to all items:

foreach (array_keys($array, 'strawberry') as $key) {
    unset($array[$key]);
}

Deleting an element from an array in PHP

There are different ways to delete an array element, where some are more useful for some specific tasks than others.

Deleting a single array element

If you want to delete just one array element you can use unset() or alternatively \array_splice().

If you know the value and don’t know the key to delete the element you can use \array_search() to get the key. This only works if the element does not occur more than once, since \array_search returns the first hit only.

unset()

Note that when you use unset() the array keys won’t change. If you want to reindex the keys you can use \array_values() after unset(), which will convert all keys to numerically enumerated keys starting from 0.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
unset($array[1]);
          // ↑ Key which you want to delete

Output:

[
    [0] => a
    [2] => c
]

\array_splice() method

If you use \array_splice() the keys will automatically be reindexed, but the associative keys won’t change — as opposed to \array_values(), which will convert all keys to numerical keys.

\array_splice() needs the offset, not the key, as the second parameter.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
\array_splice($array, 1, 1);
                   // ↑ Offset which you want to delete

Output:

[
    [0] => a
    [1] => c
]

array_splice(), same as unset(), take the array by reference. You don’t assign the return values of those functions back to the array.

Deleting multiple array elements

If you want to delete multiple array elements and don’t want to call unset() or \array_splice() multiple times you can use the functions \array_diff() or \array_diff_key() depending on whether you know the values or the keys of the elements which you want to delete.

\array_diff() method

If you know the values of the array elements which you want to delete, then you can use \array_diff(). As before with unset() it won’t change the keys of the array.

Code:

$array = [0 => "a", 1 => "b", 2 => "c", 3 => "c"];
$array = \array_diff($array, ["a", "c"]);
                          // └────────┘
                          // Array values which you want to delete

Output:

[
    [1] => b
]

\array_diff_key() method

If you know the keys of the elements which you want to delete, then you want to use \array_diff_key(). You have to make sure you pass the keys as keys in the second parameter and not as values. Keys won’t reindex.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
$array = \array_diff_key($array, [0 => "xy", "2" => "xy"]);
                               // ↑           ↑
                               // Array keys which you want to delete

Output:

[
    [1] => b
]

If you want to use unset() or \array_splice() to delete multiple elements with the same value you can use \array_keys() to get all the keys for a specific value and then delete all elements.

\array_filter() method

If you want to delete all elements with a specific value in the array you can use \array_filter().

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
$array = \array_filter($array, static function ($element) {
    return $element !== "b";
    //                   ↑
    // Array value which you want to delete
});

Output:

[
    [0] => a
    [1] => c
]

How to delete array of array if particular key doesn't exist in it?

You can use array_filter to remove entries which don't have an answer_id:

$output = array_filter($input, function ($a) { return isset($a['answer_id']); });

Demo on 3v4l.org

How can I remove a key and its value from an associative array?

You can use unset:

unset($array['key-here']);

Example:

$array = array("key1" => "value1", "key2" => "value2");
print_r($array);

unset($array['key1']);
print_r($array);

unset($array['key2']);
print_r($array);

Output:

Array
(
    [key1] => value1
    [key2] => value2
)
Array
(
    [key2] => value2
)
Array
(
)

Remove Specific key value pair from PHP array

You can use array_diff_assoc() for that, that compares both the values and the keys:

$result = array_diff_assoc($original, $to_remove);

Example code:

$removeArray = array(
    'word'=>45,
    'number'=>112,
    'sign'=>2167
);

$originalArray = array(
    'lorem'=>2343,
    'ipsum'=>433,
    'word'=>78,
    'number'=>112,
    'sign'=>2167
);

$result = array_diff_assoc($originalArray, $removeArray);

Result:

Array
(
    [lorem] => 2343
    [ipsum] => 433
    [word] => 78
)

PHP remove specific item from array

With array_search you can get the first matching key of the given value, then you can delete it with unset.

if (false !== $key = array_search(401, $array)) {
  unset($array[$key]);
}

How to find a value in an array and remove it by using PHP array functions?

To search an element in an array, you can use array_search function and to remove an element from an array you can use unset function. Ex:

<?php
$hackers = array ('Alan Kay', 'Peter Norvig', 'Linus Trovalds', 'Larry Page');

print_r($hackers);

// Search
$pos = array_search('Linus Trovalds', $hackers);

// array_seearch returns false if an element is not found
// so we need to do a strict check here to make sure
if ($pos !== false) {
    echo 'Linus Trovalds found at: ' . $pos;

    // Remove from array
    unset($hackers[$pos]);
}

print_r($hackers);

You can refer: https://www.php.net/manual/en/ref.array.php for more array related functions.

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