help in understanding string / integer concatenation

Hello all; I am a new PHP user. (But not new at programing.) I'm running Win XP, Apache, PHP 5.0.3 (and PostgreSQL 8, not that that should make a difference). I'm trying to use PHP to generate drop down lists of arbitrary length in a form (<select> and <option>) I've come across something strange, to me, in using the concatenation (.) operator. A simplified piece of code follows. My question is, why is the output different between the two versions? apologies if I've missed something in the list archives. Thanks in advance. Ray <html> <head> <title>Untitled</title> </head> <body> <?PHP $i=4; $str = 'hello "' . $i+1 . '"'; echo $str; ?> </body> </html> output: -------------------- 1" or, version 2, same as above except break $str = 'hello "' . $i+1 . '"'; into $str = 'hello "'; $str .= $i+1 . '"'; output becomes: -------------------- hello "5" (this is what I want to see) IE vs. netscape makes no difference.