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Can we make str_(starts|ends)_with variadic?

php.internals

Hans Henrik Bergan

1 year ago

Can we make  str_(starts|ends)_with variadic?
PR: https://github.com/php/php-src/pull/18825
Code like
```php
if (str_starts_with($url, "http://") || str_starts_with($url, "https://")) {
// url
}
if (str_ends_with($filename, ".pdf") || str_ends_with($filename,
".doc") || str_ends_with($filename, ".docx")) {
// document
}
$isValidExtension = false;
foreach ($validExtensions as $needle) {
if (str_ends_with($str, $needle)) {
$isValidExtension = true;
break;
}
}
if ($isValidExtension) {
// valid extension
}
```
could then be replaced with
```
if (str_starts_with($url, "http://", "https://")) {
// url
}
if (str_ends_with($filename, ".pdf", ".doc", ".docx")) {
// document
}
if(str_ends_with($str, ...$validExtensions){
// valid extension
}
```

Fwiw Python support str.endswith((".pdf", ".doc", ".docx"))

Niels Dossche

1 year ago

I think I like it, it seems convenient and I had to do stuff like this in the past using a loop.
I don't immediately see a technical reason why this would be a bad idea.

Kind regards
Niels

Christian Schneider

1 year ago

Am 10.06.2025 um 21:46 schrieb Hans Henrik Bergan <hans@loltek.net>:

> Can we make  str_(starts|ends)_with variadic?
> ```
> if (str_starts_with($url, "http://", "https://")) {
>    // url
> }
> if (str_ends_with($filename, ".pdf", ".doc", ".docx")) {
>    // document
> }
> if(str_ends_with($str, ...$validExtensions){
>    // valid extension
> }
> ```

Hmm, being old-fashioned I would probably do this with a regex:
str_starts_with($url, "http://", "https://")	=>	preg_match('#^https?://#', $url)
str_ends_with($filename, ".pdf", ".doc", ".docx")	=>	preg_match('#\.(pdf|doc|docx)$#', $filename)
str_ends_with($str, ...$validExtensions)	=>	preg_match('#\.(' . implode('|', array_map(fn($v) => preg_quote($v, '#'), $ validExtensions)) . ')$#', $str)

And even though the variadic versions could easily be implemented in user-land I see your point about your version being clearer and less error-prone, even though my old brain is worried about a hidden loop (but that's an implementation detail and can be avoided if one really wants to).

Another way of thinking about it would be
array_any($validExtensions, fn($ext) => str_ends_with($str, $ext))
which is quite concise as well and avoids reimplementing iteration for individual functions separately.

Which leaves me +-0 on this,
- Chris

Tim Düsterhus

1 year ago

Hi

Am 2025-06-11 11:58, schrieb Christian Schneider:

> Am 10.06.2025 um 21:46 schrieb Hans Henrik Bergan <hans@loltek.net>:
>> Can we make  str_(starts|ends)_with variadic?
>> ```
>> if (str_starts_with($url, "http://", "https://")) {
>>    // url
>> }
>> if (str_ends_with($filename, ".pdf", ".doc", ".docx")) {
>>    // document
>> }
>> if(str_ends_with($str, ...$validExtensions){
>>    // valid extension
>> }
>> ```
>
> […]
>
> Which leaves me +-0 on this,
> - Chris

I agree that the examples are not particularly well-chosen, because the
correct implementation for the two examples would be:


if (\in_array(\pathinfo($filename, PATHINFO_EXTENSION), ['pdf',
'doc', 'docx'], true)) { }

and

if (\in_array(\Uri\Rfc3986\Uri::parse($url)?->getScheme(), ['http',
'https'], true)) { }

and then leaving it up to the code developers / the engien to possibly
optimize `\in_array()` into `match()` or similar when only a small
number of values need to be matched.

Best regards
Tim Düsterhus