On Jun 25, 2024, at 4:51 PM, Gina P. Banyard <
[email protected] <
mailto:[email protected]>> wrote:
On Tuesday, 25 June 2024 at 19:06, Mike Schinkel <
[email protected] <
mailto:[email protected]>> wrote:
For this exact case of extracting a file name without an extension, you should really just use:
|pathinfo($filepath, PATHINFO_FILENAME);|
But for something more generic, you can just do:
explode($delimiter, $str)[0];
So I really don't see why we would need an "str_left()" function.
Ah, *the dangers of providing a specific example of a broader use-case* is that someone will invariably discredit the specific example instead of focusing on the applicability for the broader use-case. 🤦♂️
To wit, here are seven (7) use-cases for which
pathinfo() is not a viable alternative:
https://3v4l.org/RDYFs#v8.3.8 <https://3v4l.org/RDYFs#v8.3.8>
Note those seven use-cases are found in around the first 25 results when searching GitHub for "strtok(". I could probably find more if I kept looking:
https://github.com/search?q=strtok%28+language%3APHP+&type=code
<https://github.com/search?q=strtok%28+language%3APHP+&type=code>
Regarding explode($delimiter, $str)[0] — unless it is to be special-cased during compilation —it is a really inefficient way to find the substring up to the first character, especially for large strings and/or when in a tight loop where the explode is contained in a called function.
Here is a benchmark (https://onlinephp.io/c/87341 <
https://onlinephp.io/c/87341>) showing that — on average of the runs I performed — for using
strtok() to fully process through a 3972 byte file with 359 commas it took right at */90 times/* longer using explode($delimiter, $str)[0] vs. strtok($str,$delimiter). Imagine is the file were 39,720 bytes, or larger, instead.
Size of file: 3972
Number of commas: 359
Time taken for strtok: 0.0034 seconds
Time taken for explode: 0.3036 seconds
*Times strtok() faster: 89.1*
Yes the above processes the entire file using explode()[0] each time rather than first using explode(",") once — because of the equivalent of the N+1 problem[1] where the explode() is buried in a function. This illustrates why strtok() is so good for its primary use-case of parsing text files. strtok() is fast and does not use heaps of memory on every token.
This leads me to think
strtok() */should not/* be deprecated given how inefficient string handling in PHP can otherwise be, at least not without a much more efficient object for string parsing.