unexpected preg_replace behavior

[yawnmoth]

say i have the following script:

<?
$test = "aaaaa";
print '"' . preg_replace('/.*/','x',$test) . '"<br>';
$test = "\n\n\n\n\n ";
print '"' . preg_replace('/.*/','x',$test) . '"';
?>

the output i would expect is as follows:

"x"<br>"x"

the output i actually get follows:

"xx"<br>"x
x
x
x
x
x"

so why the difference? why do i get two x's instead of one x for the
first preg_replace, and why does the preg_replace for the new line
characters not give me the same thing as the first preg_replace?

[Pedro Graca]

Re: unexpected preg_replace behavior

yawnmoth wrote:[color=blue]
> say i have the following script:
>
> <?
> $test = "aaaaa";
> print '"' . preg_replace('/.*/','x',$test) . '"<br>';[/color]

Somehow preg_replace breaks "aaaaa" into "aaaaa" and "" (the empty
string). I checked with

$n = preg_match_all( '/.*/', $test, $matches);
echo $n, ' matches: '; print_r($matche s);

I couldn't find a modifier to stop that behaviour, but maybe you can
change your preg_replace to

preg_replace('/.+/', 'x', $test)

matching 1 or more characters instead of 0 or more.
[color=blue]
> $test = "\n\n\n\n\n ";
> print '"' . preg_replace('/.*/','x',$test) . '"';[/color]

The regular expression "." does not match "\n" unless you say so with
the "/s" modifier

preg_replace('/.*/s', 'x', $test)

Like this (with "*") it will match twice: for "\n\n\n\n\n " and ""
Maybe you'd like to change the "*" to a "+" here too.
[color=blue]
> ?>
>
> the output i would expect is as follows:
>
> "x"<br>"x"
>
> the output i actually get follows:
>
> "xx"<br>"x
> x
> x
> x
> x
> x"
>
> so why the difference? why do i get two x's instead of one x for the
> first preg_replace, and why does the preg_replace for the new line
> characters not give me the same thing as the first preg_replace?[/color]

See above :)

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