How to set this if isset function - php

Question

I have the following code that sets a background if user has uploaded to database. If user has NOT uploaded an image then the result is a blank img src=''
I need to set this as an if isset function so I can plug in an alternate image if user has not uploaded anything.
Here is the current code:
<div id="background"><?php echo isset($background_image) && file_exists(ROOT.$background_image)?"<img src='$background_image' alt='' />":'';?></div>

Answer 1

Your code's a little dirty, opening php and closing it mid-html tag is only going to make it confusing for you in the future.
You're echoing back an isset which is just echo'ing back a boolean.
Try this;
$background_image = ""; // Not sure what you're using here - their username? Dump it in here anyway.
if (file_exists($background_image))
{
echo " <div id=\"background\">
<img src=\"{$background_image}\" alt=\"\" title=\"\" />
</div>";
}
Hope this helps.
Eoghan

Answer 2

I'm not sure what you mean, but a another aproach to what you are trying to do would be:
<div id="background">
<?php
$optionalImage = 'background.png';
$userImage = getUserImage();
if(empty($userImage)) {
$userImage = $optionalImage;
}
?>
<img src="<?php echo $userImage; ?>" />
</div>

Answer 3

Is it really neccessary to set the blank source of the image?
But a understandable and corrected code of what you are attempting is this
<div id="background">
<?php
echo "<img src='";
echo isset($background_image) && file_exists(ROOT.$background_image) ? $background_image : '';
echo "' alt='' />";
?>
</div>
The problem was that, either you were echo entire <img> tag, or just display ' '(Blank) with attached endings.
The short form:
echo "<img src='".(isset($background_image) && file_exists(ROOT.$background_image) ? $background_image : '')."' alt='' />";