PHP变量值更改

Question

This problem is simpler to explain with the code. Note that functions are located in a different file and are being included on the page.

$announcements = $dbc->query($q)->results(); //Returns array of objects
$announcements = prepareMessage($announcements); //Adds html tags to values
$latest = $announcements[0]; //Assign first index to variable
$announcements = truncate($announcements); //Truncate announcement text

function prepareMessage($message) {
    foreach($message as $values => $key) {
        $key->title = '<h2>'.$key->title.'</h2>';
        $key->name = '<p>'.$key->name.'</p>';
        $key->date = '<small>'.humanDate($key->date).'</small>';
    }

    return $message;
}

function truncate($message) {
    foreach($message as $values => $key) {
        $key->announcement = substr($key->announcement, 0, 50) . '...</p>';
    }

    return $message;
}

The value of the $latest variable changes after I run this line of code

$announcements = truncate($announcements);

$latest value before that line is ran

[announcement] =>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua.

$latest value after that line is ran

[announcement] =>
Lorem ipsum dolor sit amet, consectetur adipisc...

So my question is, why is the value of $latest changing?

Answer 1

Because $latest is a reference to $announcements[0], not the actual value of $announcements[0]. Instead, use a clone. In PHP5, object assignments are always by reference.

$latest = clone $announcements[0]; //Clone first object in array