带有混合文本和变量的PHP str_replace？

I have a function and within the function I have:

$clean_dir = str_replace("temp_images/".$foldername."/output/", "", $dir);

$foldername value is outside the function.

When I run the above temp_images/xyz/output remains temp_images/xyz/output, but then I replace temp_images/xyz/output with xyz directly instead of $foldername. then it changes.

How can I insert mixed text with a variable in str_replace?

Thanks

I don't recommend using global variables. Pass $foldername as a function parameter instead:

function some_func($foldername) {
    ...
    $clean_dir = str_replace("temp_images/".$foldername."/output/", "", $dir);
    ...
}

Pass a variable with the function :

function qwerty($foldername){
 ....
 $clean_dir = str_replace("temp_images/".$foldername."/output/", "", $dir);
 ....
}
qwerty("xyz");

Other Way (not good)

use global $foldername; inside function to get $foldername variable value if it is outside the function. Example :

$foldername="xyz";
function qwerty(){
 global $foldername;
 $clean_dir = str_replace("temp_images/".$foldername."/output/", "", $dir);
 ....
}

It's not a good practice to use global variable. Instead use the 1st example.