replace all keys in php array [duplicate]

Here we are using array_walk and through out the iteration we are replacing e to ! in key and putting the key and value in a new array.

Try this code snippet here

<?php
$firstArray = array('apple'=>'some code','beta'=>'other code','cat'=>'other code 2 ');
$result=array();
array_walk($firstArray, function($value,$key) use (&$result) {
    $result[str_replace("e", "!", $key)]=$value;
});
print_r($result);

You can stick with array_map actually. It is not really practical, but as a prove of concept, this can be done like this:

$array = array_combine(
    array_map(function ($key) {
        return str_replace('e', '!', $key);
    }, array_keys($array)),
    $array
);

We use array_keys function to extract keys and feed them to array_map. Then we use array_combine to put keys back to place.

Here is working demo.

If you got this :

$firstArray = array('apple'=>'some code','beta'=>'other code','cat'=>'other code 2 ');

You can try this :

$keys        = array_keys($firstArray);
$outputArray = array();
$length      = count($firstArray);

for($i = 0; $i < $length; $i++)
{
    $key = str_replace("e", "!", $keys[ $i ]);
    $outputArray[ $key ] = $firstArray[$keys[$i]];
}

We can iterate the array and mark all problematic keys to be changed. Check for the value whether it is string and if so, make sure the replacement is done if needed. If it is an array instead of a string, then call the function recursively for the inner array. When the values are resolved, do the key replacements and remove the bad keys. In your case pass "e" for $old and "!" for $new. (untested)

function replaceKeyValue(&$arr, $old, $new) {
    $itemsToRemove = array();
    $itemsToAdd = array();
    foreach($arr as $key => $value) {
        if (strpos($key, $old) !== false) {
            $itemsToRemove[]=$key;
            $itemsToAdd[]=str_replace($old,$new,$key);
        }
        if (is_string($value)) {
            if (strpos($value, $old) !== false) {
                $arr[$key] = str_replace($old, $new, $value);
            }
        } else if (is_array($value)) {
            $arr[$key] = replaceKeyValue($arr[$key], $old, $new);
        }
    }
    for ($index = 0; $index < count($itemsToRemove); $index++) {
        $arr[$itemsToAdd[$index]] = $itemsToRemove[$index];
        unset($arr[$itemsToRemove[$index]]);
    }
    return $arr;
}

Another option using just 2 lines of code:

Given:

$array
(
    [apple] => some code
    [beta] => other code
    [cat] => other code 2 
)

Do:

$replacedKeys = str_replace('e', '!', array_keys($array));
return array_combine($replacedKeys, $array);

Explanation:

str_replace can take an array and perform the replace on each entry. So..

1. array_keys will pull out the keys (https://www.php.net/manual/en/function.array-keys.php)
2. str_replace will perform the replacements (https://www.php.net/manual/en/function.str-replace.php)
3. array_combine will rebuild the array using the keys from the newly updated keys with the values from the original array (https://www.php.net/manual/en/function.array-combine.php)