PHP Regexp negative lookahead

Question

I'm trying match all words wrapped with { } but not the words with "_loop". I can't see where I'm going wrong with my reg expression. ``` $content = '

{prim_practice_name}

{prim_content}

Our Locations Are {location_loop}{name} - {state}
{/location_loop}

'; $pattern = '/\{(\w*(?!\_loop))\}/'; ```

Accepted Answer

This happens because \w* "eats" the stopping word "_loop" before your check, to prevent that you should check the word first (before \w*), like the following:

```
$pattern = '/\{((?!\w*_loop\})\w*)\}/';
```

or you can use: `?< !` :

```
$pattern = '/\{(\w*(?<!_loop))\}/';
```

PHP Regexp negative lookahead

Solution

Problem