SimpleXML - echo / print_r return different values

问题:

I am trying to convert some xml into a json object using PHP.

This should be working, yet for some bizarre reason it is failing.

Could someone provide some input.

// Loop Through images and return the right one.
$i = 1;
foreach($page->image as $image) {
    if ($i == $_GET['id']) {
         echo json_encode(array(
            'background' => $image['bgColor'],
            'image' => $image['source'],
            'caption' => $image['caption']
         ));
    }
    $i++;
}

This code returns the following.

{"background":{"0":"000033"},
 "image":"0":"0210e849f02646e2f5c08738716ce7e8b3c1169112790078351021245495.jpg"},
 "caption":   {"0":"Frog"}}

print_r($image['bgColor']); shows 'SimpleXMLElement Object ( [0] => 000033 )'

echo $image['bgColor']; shows '000033'

How do I parse values like the echo statement instead of the print_r statement. Why are these different?

回答1:

Why are these different

Because these variables are not strings internally, but SimpleXMLElement type objects that get converted into strings when output by echo.

To use the values elsewhere,I usually do an explicit cast:

$bg_color = (string) $image['bgColor'];

A canonical question regarding casting a simplexml element into a string is here:

• Forcing a SimpleXML Object to a string, regardless of context