Strange error when using single quotes instead of double quotes

MarkB423

I get the following errors:

Warning: Unexpected character in input: '\' (ASCII=92) state=1 in D:\resadmin\cyberspeed\cyberspeedsolutions.com\www\php_date.php on line 145

Parse error: parse error in D:\resadmin\cyberspeed\cyberspeedsolutions.com\www\php_date.php on line 149

Here are the lines of code:

143: if (defined('TIMEZONE_ABBREVIATION') )
144: {
145: $format = 'm-d-Y h:ia \' . makeReadable(TIMEZONE_ABBREVIATION, 1, '\');
146: }
147: else
148: {
149: $format = 'm-d-Y h:ia';
150: }

makeReadable() is one of my own functions that will basically insert a "\" between every two characters.

If you haven't noticed, the $format variable will be placed into the date() function to format the date output.

The error seems to go away when I surround all of the parse errors with double-quotes, but then the very last line of my PHP page, </HTML>, also causes a parse error which isn't even in PHP code, it is HTML.

Any ideas?

azkworld

Sure, your first \' gets interpreted as a ' which you have backslashed.
What you wanted to do is this:
$format = 'm-d-Y h:ia \' . makeReadable(TIMEZONE_ABBREVIATION, 1, '\');
Although you shouldn't really do this -- single characters are single-quoted, strings get double-quoted, so
$format = "m-d-Y h:ia \" . makeReadable(TIMEZONE_ABBREVIATION, 1, '\');

MarkB423

LOL, thanks a lot...

About the use of single quotes instead of double quotes... I've learned that when you use single quotes in PHP, it is less load on the script (though not by much) because the PHP doesn't have to search for variables to parse, whereas using double quotes allows you to make more readable code in some instances. Also, when you are printing a lot of HTML code using PHP, it is a little easier to use single quotes so you don't have to escape all of the double quotes.

I know in Java that strings require double quotes while single characters (of type "char") require you to use single quotes, but this doesn't necessarily apply to PHP...

BUT...
I am curious to know how, exactly, does PHP store variables in single quotes as opposed to double quotes? And/or does one method require more memory than the other?

azkworld

I didn't know that about double-quoted strings (being parsed for vars), but makes sense. But don't forget that even though interpreted, the script does get cached.
However, although true, I wouldn't worry about script being a bit slower -- get a faster machine. Time you will save yourself and other people potentially reading your code in the future is worth more than a CPU. I just got a new Asus HyperThreading MB with an P4 2.53/533 Ghz processor and 1GB DDR333 RAM for $500 total. Oveclocks very nicely to right about 3Ghz. Can't wait to get my 3.06 Ghz P4 with Samsung DDR533!! RAM. Should be able to overclock that baby to right about 4Ghz.
Forget about "slightly slower". 🙂

You're right that such notation is not required in PHP unlike Java, but doesn't mean it "doesn't apply". The Str/Chr notation is more or less universal across many languages, and that is a big plus in and of itself.

I find it very practical not to output a lot of html from within php. Not doing so not only makes code much more readable in source form, but also makes working in a visual dev environment much easier. Ex: echo("<TD>She said \"$line\".</TD>"); -- if you view this in something like Frontpage, Dreamweaver, or similar in WYSIWYG mode, you'll just have a tiny Script indicator.
But if you do
<TD>She said "<?=$line?>".</TD>
you do not have to backslash anything, and if you switch to visual design view in the editor, you will actually see the table with this:
She said "<?=$line?>".
as the content of one of the cells. I actually even type the vars in the visual mode -- makes reordering columns just a drag-drop operation.
Anyway, small example. 🙂

Finally, do not know it for a fact (haven't read the source), but all this quoting and slashing is purely a syntactical mechanism, I will stop using PHP in a drop if I ever find out it uses any different amount of memory depending on what notation you used to put an identical string into the memory. There are certain things programmers should be castrated for, and this would be one of them (which I'm certain is not the case).

Cheers.