How do I replace each item, without changing array's structure?

Question

$array = array('lastname', 'email', 'phone');

How do I run foreach for this array and write updated value to its place?

Like:

foreach ($array as $item) {
   // do something
   // replace old value of this item with a new one
}

---

Example:

foreach ($array as $item) {
    if (item == 'lastname')
        $item = 'firstname';
        // replace current $item's value with a 'firstname'
}

Array should become:

$array = array('firstname', 'email', 'phone');

Answer 1

In your example, a foreach loop would seem unnecessary if you know exactly what key maps to lastname, but if you need to you can still loop through the values. There are two very common ways: set the value according to the key:

foreach ($array as $key => $value) {
    if ($value == 'lastname') {
        $array[$key] = 'firstname';
    }
}

Or (PHP 5 only) use references:

foreach ($array as &$item) {
    if ($item == 'lastname') {
        $item = 'firstname';
    }
}

// Clean up the reference variable
unset($item);

Answer 2

You could do it like this:

foreach ($array as $key => $item) {
   $array[$key] = "updated item";
}

Answer 3

An alternative is to loop by reference:

foreach ($array as &$value) {
    $value = strtoupper($value);
}
unset($value);// <=== majorly important to NEVER forget this line after looping by reference...

Answer 4

foreach ($array as $i => $value) {
    if ($value == 'lastname')
        $array[$i] = 'firstname';
}