Getting error Uninitialized string offset: 0 in php - php

Question

$imageTypes = array("image/gif", "image/jpeg", "image/png","image/jpg");
$uploadData = array_shift($check);
print_r($uploadData)
Array
(
[name] => Chrysanthemum.jpg
[type] => image/jpeg
[tmp_name] => C:\xampp\tmp\phpAADE.tmp
[error] => 0
[size] => 879394
)
if(!in_array($uploadData['type'],$imageTypes)){
return false;
}
But i m getting error Uninitialized string offset: 0 in this below line
if(!in_array($uploadData['type'],$imageTypes)){

Answer 1

On your piece of code $check is undefined.
$imageTypes = array("image/gif", "image/jpeg", "image/png","image/jpg");
$uploadData = array_shift($check);
if(!in_array($uploadData['type'],$imageTypes)){
return false;
}
Maybe you have to fix by:
$imageTypes = array("image/gif", "image/jpeg", "image/png","image/jpg");
$uploadData = array_shift($imageTypes);
if(!in_array($uploadData['type'],$imageTypes)){
return false;
}

Answer 2

I think I understand what might be happening here. The value you array_shift() from the $check array might be an empty string. Consider the following example:
$imageTypes = array("image/gif", "image/jpeg", "image/png","image/jpg");
$check = array(
'' // empty string
);
$uploadData = array_shift($check);
var_dump(in_array($uploadData['type'], $imageTypes));
This raises the following warnings/notices:
PHP Warning: Illegal string offset 'type' in /Users/darragh/Sites/so.php on line 26
PHP Stack trace:
PHP 1. {main}() /Users/darragh/Sites/so.php:0
PHP Notice: Uninitialized string offset: 0 in /Users/darragh/Sites/so.php on line 26
PHP Stack trace:
PHP 1. {main}() /Users/darragh/Sites/so.php:0
Warning: Illegal string offset 'type' in /Users/darragh/Sites/so.php on line 26
Call Stack:
0.0002 227040 1. {main}() /Users/darragh/Sites/so.php:0
Notice: Uninitialized string offset: 0 in /Users/darragh/Sites/so.php on line 26
Call Stack:
0.0002 227040 1. {main}() /Users/darragh/Sites/so.php:0
bool(false)
Example: https://eval.in/134971
Note that your notice PHP Notice: Uninitialized string offset: 0 is in there, amongst other things.
Either way, you should make your code robust, perhaps raise an exception or deal with the error in your preferred manner. Something like:
$uploadData = array_shift($check);
// die if the data is not an array or if it does not have the expected key
if (!is_array($uploadData) || !array_key_exists('type', $uploadData)) {
exit('$uploadData is not a valid array!');
}
// etc.
return !in_array($uploadData['type'], $imageTypes);
Example: https://eval.in/134972
Hope this helps.