Str replace question

scialom

Hello,

I have this string:

$question = In #Year capital#, what is the capital of #Country#?

then I have this array:

       $replace[0] = "2011";
       $replace[1] = "UK";

Now I want to replace the #Year capital# on $question with $replace[0] and #Country# with $replace[$1]

Now some times it can be more than two items to replace (so the $replace array will have more keys)

I tried something like this:

 $q = preg_replace("/#(.*)#/Usi", $replace[0],$question);
 $q = preg_replace("/#(.*)#/Usi", $replace[1],$question);

but it doesn't work.
Is there a way to do so?

Many thanks!

Ashley_Sheridan

Why are you using preg_replace for this when str_replace would do. The find/replace arguments can be arrays, which is what you want to do here. You don't seem to be doing anything (at least in your example) that requires a regular expression.

scialom

thanks for your answer.
the regular expression is anything between the ##

Ashley_Sheridan

That's still not answering the question why you can't use str_replace() ? Is it the case that you don't know in advance what might be between the hash/sharp signs? If so, then you can also use arrays in preg_replace too, and the second example on the PHP manual page should be what you need: http://uk.php.net/manual/en/function.preg-replace.php

NogDog

If you need to use regexp, you could do:

$q = preg_replace('/#.*#(.*)#.*#/isU', $replace[0].$1.$replace[1], $question);

But if the place-holder values are known (i.e. the 2nd one will always be "#Country", then Ashley's point is well-taken, and could easily be done as:

$replace = array(
   '#Year capital#' => '2011',
   '#Country#' => 'UK'
);
$q = str_replace(array_keys($replace), $replace, $question);

scialom

thank you for your help

No I don't know what is in the ## so it could be #Country# or any other string.
when I use you code I get a run time error

what is the $1 in between $replace[0] $replace[1]?

NogDog

The first sub-pattern -- part of pattern within parentheses -- will be captured in $1, the next (if any) in $2, and so forth. You may need to put it in single quotes:

$q = preg_replace('/#.*#(.*)#.*#/isU', $replace[0].'$1'.$replace[1], $question);

scialom

and what if I have more then 2 items?
I don't know how many times I will have ## that need to replaced

Ashley_Sheridan

Well you must know something in advance, or how would you know what you're placing things with?