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

Question

How to find if a value exists in an array and then remove it? After removing I need the sequential index order.

Are there any PHP built-in array functions for doing this?

Answer 1

<?php
$my_array = array('sheldon', 'leonard', 'howard', 'penny');
$to_remove = array('howard');
$result = array_diff($my_array, $to_remove);
?>

Answer 2

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.

Answer 3

You need to find the key of the array first, this can be done using array_search()

Once done, use the unset()

<?php
$array = array( 'apple', 'orange', 'pear' );

unset( $array[array_search( 'orange', $array )] );
?>

Answer 4

Just in case you want to use any of mentioned codes, be aware that array_search returns FALSE when the "needle" is not found in "haystack" and therefore these samples would unset the first (zero-indexed) item. Use this instead:

<?php
$haystack = Array('one', 'two', 'three');
if (($key = array_search('four', $haystack)) !== FALSE) {
  unset($haystack[$key]);
}
var_dump($haystack);

The above example will output:

Array
(
    [0] => one
    [1] => two
    [2] => three
)

And that's good!

Answer 5

You can use array_filter to filter out elements of an array based on a callback function. The callback function takes each element of the array as an argument and you simply return false if that element should be removed. This also has the benefit of removing duplicate values since it scans the entire array.

You can use it like this:

$myArray = array('apple', 'orange', 'banana', 'plum', 'banana');
$output = array_filter($myArray, function($value) { return $value !== 'banana'; });
// content of $output after previous line:
// $output = array('apple', 'orange', 'plum');

And if you want to re-index the array, you can pass the result to array_values like this:

$output = array_values($output);

Answer 6

This solution is the combination of @Peter's solution for deleting multiple occurences and @chyno solution for removing first occurence. That's it what I'm using.

/**
 * @param array $haystack
 * @param mixed $value
 * @param bool $only_first
 * @return array
 */
function array_remove_values(array $haystack, $needle = null, $only_first = false)
{
    if (!is_bool($only_first)) { throw new Exception("The parameter 'only_first' must have type boolean."); }
    if (empty($haystack)) { return $haystack; }

    if ($only_first) { // remove the first found value
        if (($pos = array_search($needle, $haystack)) !== false) {
            unset($haystack[$pos]);
        }
    } else { // remove all occurences of 'needle'
        $haystack = array_diff($haystack, array($needle));
    }

    return $haystack;
}

Also have a look here: PHP array delete by value (not key)

Answer 7

The unset array_search has some pretty terrible side effects because it can accidentally strip the first element off your array regardless of the value:

        // bad side effects
        $a = [0,1,2,3,4,5];
        unset($a[array_search(3, $a)]);
        unset($a[array_search(6, $a)]);
        $this->log_json($a);
        // result: [1,2,4,5]
        // what? where is 0?
        // it was removed because false is interpreted as 0

        // goodness
        $b = [0,1,2,3,4,5];
        $b = array_diff($b, [3,6]);
        $this->log_json($b);
        // result: [0,1,2,4,5]

If you know that the value is guaranteed to be in the array, go for it, but I think the array_diff is far safer. (I'm using php7)

Answer 8

$data_arr = array('hello', 'developer', 'laravel' );


// We Have to remove Value "hello" from the array
// Check if the value is exists in the array

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



# output:
// It will Return unsorted Indexed array
print( $data_arr )


// To Sort Array index use this
$data_arr = array_values( $data_arr );


// Now the array key is sorted

Answer 9

First of all, as others mentioned, you will be using the "array_search()" & the "unset()" methodsas shown below:-

<?php
$arrayDummy = array( 'aaaa', 'bbbb', 'cccc', 'dddd', 'eeee', 'ffff', 'gggg' );
unset( $arrayDummy[array_search( 'dddd', $arrayDummy )] ); // Index 3 is getting unset here.
print_r( $arrayDummy ); // This will show the indexes as 0, 1, 2, 4, 5, 6.
?>

Now to re-index the same array, without sorting any of the array values, you will need to use the "array_values()" method as shown below:-

<?php
$arrayDummy = array_values( $arrayDummy );
print_r( $arrayDummy ); // Now, you will see the indexes as 0, 1, 2, 3, 4, 5.
?>

Hope it helps.

Answer 10

Okay, this is a bit longer, but does a couple of cool things.

I was trying to filter a list of emails but exclude certain domains and emails.

Script below will...

1. Remove any records with a certain domain
2. Remove any email with an exact value.

First you need an array with a list of emails and then you can add certain domains or individual email accounts to exclusion lists.

Then it will output a list of clean records at the end.

//list of domains to exclude
$excluded_domains = array(
    "domain1.com",
);

//list of emails to exclude
$excluded_emails = array(
    "bob@domain2.com",
    "joe@domain3.com",    
);

function get_domain($email) {

    $domain = explode("@", $email);
    $domain = $domain[1];
    return $domain;

}

//loop through list of emails
foreach($emails as $email) {

    //set false flag
    $exclude = false;

    //extract the domain from the email     
    $domain = get_domain($email);

    //check if the domain is in the exclude domains list
    if(in_array($domain, $excluded_domains)){
        $exclude = true;
    }

    //check if the domain is in the exclude emails list
    if(in_array($email, $excluded_emails)){
        $exclude = true;
    } 

    //if its not excluded add it to the final array
    if($exclude == false) {
        $clean_email_list[] = $email;
    }

    $count = $count + 1;
}

print_r($clean_email_list);

Answer 11

To find and remove multiple instance of value in an array, i have used the below code

$list = array(1,3,4,1,3,1,5,8);

$new_arr=array();

foreach($list as $value){

    if($value=='1')
    {
        continue;
    }
    else
    {
        $new_arr[]=$value;
    }     
}


print_r($new_arr);