note 664 deleted from String functions by torben

One important thing to be aware of when dealing with strings is the meaning of special character sequences and the difference between using _single quotes_ and _double quotes_. A "normal" string assignment looks like this: $str = "Some string..."; As you probably already noticed elsewhere in this manual you could also use $name = "Joe"; $str = "Hello $name"; // results in "Hello Joe" Now it gets a bit tricky: If your string contains certain special character sequences beginning with a backslash (often referred to as "escape sequences" or "control codes" or similar), PHP will evaluate them and act accordingly. The most useful control codes are t and n. t results in a "TAB", while n inserts a newline. So... echo "Hello $namenWelcome totwonderland" Will give something like Hello Joe Welcome to( t a b ) wonderland (Naturally, it won't show up this way in your browser unless its inside a <PRE> </PRE> block.) Of course, if you already know any other language like C or JAVA, all this won't tell you anything new. There is a pitfall however, that when e.g. you want to store Windows paths in a string and/or output it the behavior above may bite you. Example: $win_path = "c:testmytext.txt";<br> echo $win_path; This will look like c:( t a b ) estmytext.txt in the HTML code PHP generates, because it really means "c:(TAB)mytext.txt"! Since this is probably not what you intended, you should use single quotes in this case: $win_path = 'c:testmytext.txt'; The single quotes will ensure that PHP treats this string verbatim, so the t in this example wouldn't result in a TAB. Be aware that this also prevents PHP from expanding any variables, so echo 'Hello $name'; // this outputs Hello $name ! doesn't work as you might expect. Another means of preventing special character sequences from being evaluated is "escaping" them. (BTW: This concept is also found in many other languages.) What does this mean? In the above example we could've also written: $win_path = "c:\testmytext.txt"; echo $win_path; // outputs c:testmytext.txt This effectively tells PHP not to interpret the t as a TAB. Accordingly, the same goes for \n etc. Now you may ask "Argh, do I have to really take care of this myself - Why can't PHP do it for me?" The answer is yes, it can: Just use the addslashes() function. If you want to know more about it, read the appropriate section.