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phpregexpreg-match

By using PHP preg_match, how to get specific substring from string

I would like to get substring: 

myPhotoName

from the below string:

path/myPhotoName_20170818_111453.jpg

using PHP preg_match function.

Please may somebody help me?

Thank you.

Solution

  • Preg_match from / to _. 

    $str = "blur/blur/myPhotoName_20170818_111453.jpg";
Preg_match("/.*\/(.*?)_.*(\..*)/", $str, $match);

Echo $match[1] . $match[2];

    I use .*? to match anything between the slash and underscore lazy to make sure it doesn't match all the way to the last underscore.
    Edited to make greedy match anything before the /

    https://3v4l.org/9oTuj

    Performance of regex:
    enter image description here

    Since it's such a simple pattern you can also use normal substr with strrpos.
    Edited to use strrpos to get the last /

    $str = "blur/blur/myPhotoName_20170818_111453.jpg";
$pos = strrpos($str, "/")+1; // position of /
$str = substr($str, $pos, strpos($str, "_")-$pos) . substr($str, strpos($str, "."));
// ^^ substring from pos to underscore and add extension

Echo $str;

    https://3v4l.org/d411c

    Performnce of substring:
    enter image description here

    My conclusion
    Regex is not suitable for this type of job as it's way to slow for such a simple substring pattern.