preg_replace "pattern" attribute

[turtleman8605]

Can someone try to explain the pattern attribute in the preg_replace() function? I'm trying to get it to replace a line of html with an updated line of new html, and I just don't understand how to use that parameter.

[teng84]

ereg_replace ( string $pattern, string $replacement, string $string )

[turtleman8605]

I know how it's set up. I don't understand what the pattern parameter is used for or what I should put there.

[teng84]

give us the sample string or read this http://www.php.net/manual/en/function.ereg-replace.php

[btherl]

Here's a simple example

 

$str = "Fluffy Bunnies";
$str = preg_replace("|Fluffy|", "Blood-thirsty", $str);
# Now $str is "Blood-thirsty Bunnies"

 

Slightly more complex

 

$str = "<b>Fluffy</b> Bunnies";
$str = preg_replace("|<.*>|", "Blood-thirsty", $str);
# Again, $str is "Blood-thirsty Bunnies", but for a totally different reason.

 

.* means "Any string of any characters".  So it matches the longest string starting with "<" and ending with ">".  These patterns are all identical:

 

"/<.*>/"

"+<.*>+"

 

It doesn't matter what you put at the start and end, but it must be the same each time.

[turtleman8605]

So if I want to replace an entire string, then pattern is the same as the replacement string?

[trq]

So if I want to replace an entire string, then pattern is the same as the replacement string?

 

No. That pattern must match wont you want to replace.