php print_r没有显示所有值

For sending email via php I fill an array with the body content (easier to quick comment out something). This looks like:

$DeInhoud   = array();
$DeInhoud[] = "<html>";
$DeInhoud[] = "<head>";
$DeInhoud[] = "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />";
$DeInhoud[] = "<title>Weborder</title>";
$DeInhoud[] = "</head>";
$DeInhoud[] = "<body>";
$DeInhoud[] = "whooohoooo";
$DeInhoud[] = "</body>";
$DeInhoud[] = "</html>";

When using print_r I get:

Array
(
    [0] => 
    [1] => 
    [2] => 
    [3] => 
    [4] => 
    [5] => 
    [6] => whooohoooo
    [7] => 
    [8] =>  
)

However when feeding this array to the function mail() I do get the correct content.

What do I need to do to display the content of this array?

I tried to use the escape code \ before those < but didn't help.

Your html tags are getting parsed by browser as it expects the default content-type as text/html.

Set your content-type to plain text and try dumping the variable.

header("Content-Type: plain/text");
print_r($DeInhoud);
print_r(htmlentities(implode(' ' ,$DeInhoud)));