[RESOLVED] Uninitialized string offset

[Delcypher]

Hi i'm getting a problem from a small function i wrote and i'm not sure why.

<?php
function guitartuning2array($data) {

/* converts a scale or chord structure into an array */
$sFM = array();

while(strlen($data)>0) {

//check case X# eg. F#
if($data{1}=="#") {
//add X# to array
$sFM[] = substr($data,0,2);
//remove X# from $data
$data =substr_replace($data,'',0,2);
continue;
}

//check case Xb eg. Fb
if($data{1}=="b") {
//add X# to array
$sFM[] = substr($data,0,2);
//remove X# from $data
$data =substr_replace($data,'',0,2);
continue;
}

//only possible case left is x
//add X to array
$sFM[] = substr($data,0,1);
//remove X from $data
$data = substr_replace($data,'',0,1);

//end while;
}
return $sFM;
//end function
}


$tuning_as_array = guitartuning2array("EA#DGbBE");
print_r($tuning_as_array);



?>

i get the following notice, however the script performs the task as it should.

Notice: Uninitialized string offset: 1 in e:\websrv\www\test.php on line 12

Notice: Uninitialized string offset: 1 in e:\websrv\www\test.php on line 21

these are

if($data{1}=="#") {

and i

if($data{1}=="b") {

if i use substr($data,1,1) rather than $data{1}, the script gives no warning notice.

any ideas to why this is happening??

[laserlight]

When the loop hits a string with just 1 character, $data{1} doesnt exist.

I suggest you redo it to:

function guitartuning2array($data) {
	/* converts a scale or chord structure into an array */
	$sFM = array();

$max = strlen($data) - 1;
$i = 0;
while ($i < $max) {
	switch ($data{$i+1}) {
		case '#':
		case 'b':
			$sFM[] = substr($data, $i, 2);
			$i += 2;
			break;
		default:
			$sFM[] = $data{$i};
			++$i;
	}
}
// add last character if it wasnt handled by main loop
if ($i == $max) {
	$sFM[] = $data{$max};
}
return $sFM;
}

[Delcypher]

thank you, thats a much better way of doing it. 🙂