PHP function not returning string [duplicate] - php

Question

This question already has answers here:
How to use return inside a recursive function in PHP
(4 answers)
Closed 9 months ago.
I have constructed a function that takes a filename, and increments a counter in the filename and returns it, however, everything is correct, except the return does not return the filename.
Any help, please?
My code:
$filename = join("", array_reverse($date));
$filename .= ".xml";
$dir = "../gigs";
$file = $dir."/".$filename;
function getNewFileName($filename, $dir) {
if (is_file("$dir/$filename")) {
if (strpos($filename, "_") === false) {
$filename = str_replace(".xml","_1.xml",$filename);
getNewFileName($filename, $dir);
}
else {
$pos = strpos($filename, "_");
$counter = (int)substr($filename, $pos+1,1);
$counter++;
$filename = substr($filename,0, $pos)."_".$counter.".xml";
getNewFileName($filename, $dir);
}
} else {
// echoing HERE shows that the string is manipulated correctly
return (string)$filename; // but returning here is not working
}
}
echo getNewFileName($filename, $dir); // <- this last line prints nothing out
Thanks in advance.

Answer 1

The line:
getNewFileName($filename, $dir);
needs a return:
return getNewFileName($filename, $dir);

Answer 2

This is what your function should look like:
function getNewFileName($filename, $dir) {
if (is_file("$dir/$filename")) {
if (strpos($filename, "_") === false) {
$filename = str_replace(".xml","_1.xml",$filename);
return getNewFileName($filename, $dir);
}
else {
$pos = strpos($filename, "_");
$counter = (int)substr($filename, $pos+1,1);
$counter++;
$filename = substr($filename,0, $pos)."_".$counter.".xml";
return getNewFileName($filename, $dir);
}
}
return (string)$filename;
}
echo getNewFileName($filename, $dir); // <- this last line prints nothing out

Answer 3

Firstly, please try and format your code so the indents are readable. Second, you're just not returning from recursive calls to getNewFileName():
function getNewFileName($filename, $dir) {
if (is_file("$dir/$filename")) {
if (strpos($filename, "_") === false) {
$filename = str_replace(".xml","_1.xml",$filename);
return getNewFileName($filename, $dir); // here
} else {
$pos = strpos($filename, "_");
$counter = (int)substr($filename, $pos+1,1);
$counter++;
$filename = substr($filename,0, $pos)."_".$counter.".xml";
return getNewFileName($filename, $dir); // and here
}
} else {
return (string)$filename;
}
}
assuming that's your intent.

Answer 4

function getNewFileName($filename, $dir) {
if (is_file("$dir/$filename")) {
if (strpos($filename, "_") === false) {
$filename = str_replace(".xml","_1.xml",$filename);
return (string)$filename;
} else {
$pos = strpos($filename, "_");
$counter = (int)substr($filename, $pos+1,1);
$counter++;
$filename = substr($filename,0, $pos)."_".$counter.".xml";
return (string)$filename;
}
} else {
return (string)$filename;
}
}
Your function had a loop to infinity.