replace non breaking space PHP - php

Question

* The json_encode is returning NULL? is NOT the answer. I still receive a NULL when using the json_encode.*
I am very new to PHP, so if you could edit the section with the fixed code, I'd appreciate it.
This is my problem:
When an article under "introtext" contains non breaking lines, it returns NULL. The articles that do not have a non breaking space show up just fine.
This is my question:
How can I get the articles under "introtext" to display properly even if they contain a non breaking space.
Here's the code:
$connection = mysqli_connect($host, $user, $pass);
//Check to see if we can connect to the server
if(!$connection)
{
die("Database server connection failed.");
}else{
//Attempt to select the database
$dbconnect = mysqli_select_db($connection, $db);
//Check to see if we could select the database
if(!$dbconnect)
{
die("Unable to connect to the specified database!");
}else{
$catID = $_GET['catid'];
$id = $_GET['id'];
$rtn = $_GET['rtn'];
if($id!=""){
$query = "SELECT * FROM tcp_content WHERE id=" . $id . "";
}else{
$query = "SELECT * FROM tcp_content WHERE catid=" . $catID . " ORDER BY publish_up DESC LIMIT " . $rtn . "";
}
$resultset = mysqli_query($connection,$query);
$records = array();
//Loop through all records and add them to array
while($r = mysqli_fetch_assoc($resultset))
{
$r['introtext'] = print_r($r['introtext'],true);
$records[] = $r;
}
//Output the data as JSON
echo json_encode($records);
}
}
?>
here are two links:
This link contains the non breaking space, so you'll notice introtext returns NULL
This link does NOT contain the non breaking space, so you'll notice the article shows

Answer 1

I found this link json_encode problem
see second answer. Charles is suggesting that use iconv() to remove URL encoded non-breaking space.

Answer 2

I finally figured it out and got it working
$r['introtext'] = utf8_encode($r['introtext']);
$r['introtext'] = str_replace(chr(194).chr(160),' ',$r['introtext']);
$r['introtext'] = str_replace(chr(194).chr(147),'"',$r['introtext']);
$r['introtext'] = str_replace(chr(194).chr(148),'"',$r['introtext']);
$r['introtext'] = str_replace(chr(194).chr(146),"'",$r['introtext']);
$r['introtext'] = str_replace(chr(194).chr(145),"'",$r['introtext']);
$r['introtext'] = htmlentities($r['introtext'], ENT_QUOTES | ENT_IGNORE, "UTF-8");
$records = $r;