How to convert Camelcase to snake_case in PHP (simply)?

Asked

Viewed 739 times

1

How do I convert a string with Camelcase for snake_case in PHP as simply as possible?

Example:

CamelCase => camel_case
AjaxInfo  => ajax_info
php camel-case snake-case

  • $saida = ltrim(strtolower(preg_replace('/[A-Z]/', '_$0', $entrada )), '_');

1 answer

5


Ready with a line has this one from Sozão

$saida = ltrim(strtolower(preg_replace('/[A-Z]/', '_$0', $entrada )), '_');

The question is, what happens if you do ___ at first?

But it can be interesting to change the logic if you’re always starting with a letter:

$saida = substr(strtolower(preg_replace('/[A-Z]/', '_$0', $entrada )), 1);

This one already guarantees the first character not having _ using lcfirst:

$saida = strtolower( preg_replace(
    ["/([A-Z]+)/", "/_([A-Z]+)([A-Z][a-z])/"], ["_$1", "_$1_$2"], lcfirst($entrada) ) );


Remarks:

  • Look at these situations:

    LetraEMaiuscula 
CodeIsHTML

    In the first case, use [a-z][A-Z] problem. In the second case, [a-z][A-Z] is better than just [A-Z]. If you need the second case you have to use a trade in the format ([A-Z])([A-Z][a-z]) for $1_$2

  • What if it has spaces? I believe that if it is already Camelcase well formed, it makes no sense to have spaces in the string, but if you need to exchange for _, is the case to add a str_replace(' ', '_', $valor ) as Miguel has already warned answer given.

  • The problem is if you have space. You should not replace it with '_'?

  • @Miguel good question. It depends on how the person will use it. I added a remark.

  • I realized of course that if it is Camelcase it is part of the brush that there are no spaces

  • @Miguel however I find valid his observation, fine tune, we never know how the person will use the code.

Browser other questions tagged php camel-case snake-case

You are not signed in. Login or sign up in order to post.