Create a new index array from an associative array

Here is an example of how you can create a new index array from an associative array in PHP:

$associativeArray = array(
    'name' => 'John',
    'age' => 30,
    'city' => 'New York'
);

$indexArray = array_values($associativeArray);

print_r($indexArray);

This will output:

Array
(
    [0] => name
    [1] => age
    [2] => city
)

The array_values() function returns a new array with the same values as the original array, but with numeric keys starting from 0.

Alternatively, you can use a loop to create the index array:

$associativeArray = array(
    'name' => 'John',
    'age' => 30,
    'city' => 'New York'
);

$indexArray = array();
foreach ($associativeArray as $key => $value) {
    $indexArray[] = $key;
}

print_r($indexArray);

This will also output:

Array
(
    [0] => name
    [1] => age
    [2] => city
)

Note that the array_values() function is more concise and efficient, but the loop approach can be useful if you need to perform additional operations on the keys or values.