Change $key of associative array in a foreach loop in php

Question

I have an array like this:

array(
    'firstName' => 'Joe',
    'lastName'  => 'Smith'
    )

I need to loop over every element in my array and in the end, the array should look like this:

array(
    'FirstName' => 'Joe',
    'LastName'  => 'Smith'
    )

Failed idea was:

    foreach($array as $key => $value)
    {
        $key = ucfirst($key);
    }

This obviously will not work, because the array is not passed by reference. However, all these attempts also fail:

    foreach(&$array as $key => $value)
    {
        $key = ucfirst($key);
    }


    foreach($array as &$key => $value)
    {
        $key = ucfirst($key);
    }

Pretty much at my wits end with this one. I'm using Magento 1.9.0.1 CE, but that's pretty irrelevant for this problem. If you must know, the reason I have to do this is because I have a bunch of object that's I'm returning as an array to be assembled into a SOAP client. The API I'm using requires the keys to begin with a capital letter...however, I don't wish to capitalize the first letter of my object's variable names. Silly, I know, but we all answer to someone, and that someone wants it that way.

Answer 1

unset it first in case it is already in the proper format, otherwise you will remove what you just defined:

foreach($array as $key => $value)
    {
        unset($array[$key]);
        $array[ucfirst($key)] = $value;
    }

Answer 2

You can't modify the keys in a foreach, so you would need to unset the old one and create a new one. Here is another way:

$array = array_combine(array_map('ucfirst', array_keys($array)), $array);

1. Get the keys using array_keys
2. Apply ucfirst to the keys using array_map
3. Combine the new keys with the values using array_combine