This can be caused by something else that has nothing to do with encoding, casts, conversions, etc. I ran across it while developing an error handling class. Part of the process was to create a backtrace. During development, I was printing it to the screen (using ‘pre’ tags) and to a log. The black diamond was there whenever an object’s private properties were being enumerated. This did not happen with public properties. In a browser it would look like this: ObjectNamepropName. Printed to the log, it looked like this: NULObjectNameNULpropName.

Come to find out the diamonds were actually the ASCII NULL character (a backslash followed by a zero, 0×00 in hex). I used this to clear it out:


/* Replace ASCII NULL with empty string */
$var = str_replace("\0",'',$var);

Hope this helps someone. Took me several hours and half a pack of smokes to figure it out.