Preg_Replace Question

Allen4172

I am relatively new to PHP and not sure if this is possible. Any help is greatly appreciated.

What I would like to do is use preg_replace to change all " to \" AND also add single quotes around numbers when they are in the following format: .

Am I able to do a pre_replace for both? I can't call the text via something like $string = "text" due to it causing a T_LNUMBER or T_STRING parsing errors.

Any ideas/suggestions would be greatly appreciated 🙂

Allen4172

Any php gurus out there that could possibly send me some advice? I would greatly appreciate it 🙂

laserlight

use preg_replace to change all " to \"

This can be done with [man]addslashes/man.

add single quotes around numbers when they are in the following format:

You need to clarify the format, what exactly is constant here?

Allen4172

Hi and thanks for answering 🙂

I tried the addslashes command but it actually displays the \ in the echo statement itself. I guess I should of been more precies.

Basically what I'm trying to figure out is how can I add the \ in front of all ' or " in order for the php echo statement not to give a parse error. Basically the text is from articles wrote so naturally there will be " and ' in there but I was under the impression that if you preceded it with a \ it would not give a parse error. So instead of me going into every articles and manually adding that in there, I would like to find a solution where I can auto add that into both before echo 🙂

For the . . The constant is everything but the 0, 0, 205. As those numbers will change depending on the RGB color values. I was wondering if there was some command such as [0-999], [0-999], [0-999] change to '[0-999]' ect. Hope that gives you some idea? 🙂

xblue

Matching numbers with regular expression can sometimes be nagging because they are treated as string no matter what they mean mathmatically (e.g. is one greater than the other does not mean much to regex unless in a way that string 10 is longer than 1).

However since you do not want be have the exact range between 0 and 255, but only a 1-3 digit number, it should not be that hard:

\d is a single digit, \d{1,3} is the above

Allen4172

Ok I tried something like this:

$message = preg_replace('\d{1,3}', '"\d{1,3}"', '');

It comes back with a:

"Warning: Delimiter must not be alphanumeric or backslash".

My desird output is:

The 0 0 205 are variables. So I'd like it to match 0-255 on all three and add the ". So far no luck 🙁

Weedpacket

You're missing the delimiter. The traditional choice is /. See examples 2, 3, 4, 5, 6, and 7 on the [man]preg_replace[/man] manual page for its use.

Allen4172

Ok, awseome...thanks for that...am getting it to work how I wish almost 🙂

Currently I have:

$message = preg_replace('/\d{1,3}/', '"\d{1,3}"', '');

But now instead of outputting original numbers with the newly set " before and after. It will output "\d{2,3}" . Here's the example output:

How do I set it to just add the " before and after the original numbers?

Am alot closer, am almost there but not quite 🙂

Weedpacket

Well, that's what you're asking for - you're saying "replace all sequences of one to three digits with the string "\d{1,3}". The second argument is just a string, it's not a regular expression.

Go back to [man]preg_replace[/man], have a look at Example 2, 4 and 5, and read the second and third paragraphs of the description. Have a look also at some of the user notes - there are more examples there. (Hint: $1)

Allen4172

Based on the examples, I take it the preg_replace function is not the thing I need? Since I want to take the number add the " before and the " after?

Weedpacket

You'll still need something to find the number. And once you've found it, replace it with what you want.

The replacement string you want is '"$0"'. $0 means "the thing that was matched".

Allen4172

Where can I find a list of the special expressions such as these? Evidently my book leaves out those parts. It list things like \n and other backslash characters but I see no reference to special characters such as the one you mentioned.

Thanks for the helP 🙂

Weedpacket

http://www.php.net/manual/en/reference.pcre.pattern.syntax.php Skip the section titled "Differences from Perl". If you don't know Perl's implementation then there's no point knowing what's different about it 🙂 See also the other pages in the [man]PCRE[/man] chapter and don't forget the user notes.

Be aware that regular expressions are a language in their own right. Whole books can be written on the subject. Whole books have.