PHP正则表达式不起作用 - 解析{{tags}}

Question

What I want to do it parse the following string in a way that all placeholders inside {{}} are replace by the value indicated by "default". For instance, {{time, default=noon}} should become noon .

Here's the code I tried:

$input = 'It was a {{color, default=black}} and scary {{phase}}. As the {{animals, default=dogs}} {{make_sound, default=barked}} and the trees swayed {{setting, default=to the breeze}}, a {{size, default=}} {{monster, default=troll}} that emerged from the shadows.';
$input = preg_replace('/\{\{.*default=(\w+)\}\}/i', '$1', $input);
echo $input;

The output produced is: Output: It was a troll that emerged from the shadows.

Why are the remaining patterns not getting parsed correctly?

Answer 1

{{[^}]*\bdefault=([^}]*)}}

You can try this.Replace by $1 .See demo.

https://regex101.com/r/aG0sF5/4

Answer 2

Because .* is greedy. And also a non-greedy regex .*? won't work here because .*? will also match }} .

preg_replace('/\{\{(?:(?!\}\}).)*?default=(.*?)\}\}/i', '\1', $input);

DEMO

Answer 3

please see the Demo

=(.*?)}

Debuggex Demo