PHP array referencing issue

Question

I am ignorant to what is happening!

Here is the error:

Warning: Parameter 2 to mysqli_stmt::bind_param() expected to be a reference, value given in C:\xxxx\htdocs\xxxxx\xxxxx\class.mysql.php on line 51
Fatal error: Uncaught exception 'ReflectionException' with message 'Invocation of method mysqli_stmt::bind_param() failed' in C:\xampp\htdocs\assemblyx.net\class\class.mysql.php:51 Stack trace: #0 C:\xxxx\htdocs\xxxxx\xxxxx\class.mysql.php(51): ReflectionMethod->invokeArgs(Object(mysqli_stmt), Array) #1 C:\xxxx\htdocs\xxxxx\xxxxx\index.php(17): mysql->Insert('test', Array) #2 {main} thrown in C:\xxxx\htdocs\xxxxx\xxxxx\class.mysql.php on line 51

Code in index.php:

$a=array();
$a[0]=array();
$a[0]["test_value"]="helloMysqli";
$a[0]["test_int"]="2";
$a[0]["test_dec"]="3.1";
$db->Insert("test", $a);

Method in class.mysql.php:

function Insert($table, $arrInsert){
 $types = $cols = $q = "";
 $value = array();
 foreach($arrInsert as $k => $v){
 foreach($v as $k2 => $v2){
 $cols .= ($cols=="")?$k2:", ".$k2;
 $q .= ($q=="")?"?":", ?";
 $value[] = $v2;
 $types .= substr(gettype($v2),0,1);
 }
 }
 $sql = "insert into ".$table." (".$cols.") value (".$q.");";
 $stmt = $this->prepare($sql);
 $refArr = array();
 $refArr[0] = $types;
 foreach($value as $k => $v){
 $refArr[] = $v;
 }
 $ref = new ReflectionClass('mysqli_stmt'); 
 $method = $ref->getMethod("bind_param");
 $method->invokeArgs($stmt,$refArr); 
 $stmt->execute();
}

Now if I code the array into the Insert method every works fine:

function Insert($table, $arrInsert){
 $types = $cols = $q = "";
 $value = array();
 foreach($arrInsert as $k => $v){
 foreach($v as $k2 => $v2){
 $cols .= ($cols=="")?$k2:", ".$k2;
 $q .= ($q=="")?"?":", ?";
 $value[] = $v2;
 $types .= substr(gettype($v2),0,1);
 }
 }
 $sql = "insert into ".$table." (".$cols.") value (".$q.");";
 $stmt = $this->prepare($sql);
 $refArr = array();
 $refArr[] = $types;
 foreach($value as $k => $v){
 $refArr[] = $v;
 }
//****************
// added array here
//***************** 
 $refArr = array();
 $refArr[] = "sss";
 $refArr[] = "helloMysqli";
 $refArr[] = "2";
 $refArr[] = "3.1";
 $ref = new ReflectionClass('mysqli_stmt'); 
 $method = $ref->getMethod("bind_param");
 $method->invokeArgs($stmt,$refArr); 
 $stmt->execute();
}

I am obviosly not understanding how the array is being referenced. Please someone enlighten me!

Here are the print_r outputs to show that both arrays are outputting the same:

 function Insert($table, $arrInsert){
 $types = $cols = $q = "";
 $value = array();
 foreach($arrInsert as $k => $v){
 foreach($v as $k2 => $v2){
 $cols .= ($cols=="")?$k2:", ".$k2;
 $q .= ($q=="")?"?":", ?";
 $value[] = $v2;
 $types .= substr(gettype($v2),0,1);
 }
 }
 $sql = "insert into ".$table." (".$cols.") value (".$q.");";
 $stmt = $this->prepare($sql);
 $refArr = array();
 $refArr[] = $types;
 foreach($value as $k => $v){
 $refArr[] = $v;
 }
 print_r($refArr);
 exit;
// print_r output : Array ( [0] => sss [1] => helloMysqli [2] => 2 [3] => 3.1 )
 $refArr = array();
 $refArr[] = "sss";
 $refArr[] = "helloMysqli";
 $refArr[] = "2";
 $refArr[] = "3.1";
// print_r output : Array ( [0] => sss [1] => helloMysqli [2] => 2 [3] => 3.1 )
 $ref = new ReflectionClass('mysqli_stmt'); 
 $method = $ref->getMethod("bind_param");
 $method->invokeArgs($stmt,$refArr); 
 $stmt->execute();
 }

• the_pete: If you do a print_r($value); prior to the foreach() loop foreach($value as $k => $v){.... what are you seeing? It would be nice to know that you did some kind of error checking prior to just tossing a question up here.
• AssemblyX: I did a var_dump on both arrays, they both returned the exact same value, is var_dump equivalent to print_r?
• the_pete: print_r is "human readable", but what comes back form those arrays? It could be that your foreach loop is incorrect but again, we can't help without knowing what you are seeing.
• AssemblyX: I have tested this over and over, they both bring back the exact same result, just did a print_r : Array ( [0] => sss [1] => helloMysqli [2] => 2 [3] => 3.1 )
• the_pete: What does $refArr look like after $refArr[] = $types; and again after the foreach loop where you also try and add the values from $values to it, and also, what does $values look like before the foreach loop?

Answer 1

When I add & in the forloop to look like this it works:

foreach($value as $k => $v){$refArr[] = &$value[$k];}