Another example of something to watch out for when using references with arrays. It seems that even an usused reference to an array cell modifies the *source* of the reference. Strange behavior for an assignment statement (is this why I've seen it written as an =& operator? - although this doesn't happen with regular variables).
$array1 = array(1,2);
$x = &$array1; $array2 = $array1; $array2=22; print_r($array1);
 => 1
 => 22 // var_dump() will show the & here
//above was Noted By Dave at SymmetricDesign dot com//
//and below is my opinion to this simple problem. //
This is an normal referencing problem.
when you gain an reference to a memory at some variable.
this variable, means "memory itself". (in above example, this would be -> $x = &$array1; // Unused reference)
and you've copied original one($array1) to another one($array2).
and the copy means "paste everything on itself". including references or pointers, etcs. so, when you copied $array1 to $array2, this $array2 has same referencers that original $array1 has. meaning that $x = &$array1 = &$array2;
and again i said above. this reference means "memory itself".
when you choose to inserting some values to $array2,
$x; reference is affected by $array2's value. because, in allocated memory, $array2 is a copy of $array1. this means that $array2 = $array1, also means &$array2 = &$array1 as said above. this causes memory's value reallocation on $array1. at this moment. the problem of this topic is cleared by '$x', the memory itself. and this problem was solved by unsetting the '$x'. unsetting this reference triggers memory reallocation of $array2. this closes the reference link between the copied one($array1, which is the original) and copy($array2). this is where that bug(clearly, it's not a bug. it's just a missunderstanding) has triggered by. closing reference link makes two array object to be separated on memory. and this work was done through the unset() function. this topic was posted 7 years ago, but i just want to clarify that it's not a bug.
if there's some problems in my notes, plz, note that on above.