PHP variables not changing outside of function - php

Question

I have a function in PHP. I am passing two arrays to the function as references. While the function updates $array2 outside the function, it does not update $array. Below is my function.
function JobAssign($i,&$array,&$array2,$Machine_Interchange) {
$compmachine = $array[$i]['Machine_Name'];
$CLT = $array[$i]["Estimated_Start_Date"];
$ET = $array[$i]["Estimated_Completion_Date"];
$Machine = $array[$i]['Machine_Name'];
$Compatibility_sql = "SELECT Machine2 FROM Machine_Interchange where Machine1 = '$Machine' and Value = 1";
$compatibility_query = mysql_query($Compatibility_sql) or die(mysql_error());
for($i=0; $compatibility[$i] = mysql_fetch_assoc($compatibility_query);$i++);
array_pop($compatibility);
$maxkey = max(array_keys($compatibility));
$maxnumber = max(array_keys($array2))+1;
$k=0;
do{
$compmachine = $compatibility[$k]['Machine2'];
$CLT = $array2[$compmachine];
if($array2[$compatibility[$k]['Machine2']]>$array2[$compatibility[$k+1]['Machine2']]) {
$compmachine = $compatibility[$k+1]['Machine2'];
$CLT = $array2[$compatibility[$k+1]['Machine2']];
}
$k=$k+1;
}
while($k<$maxkey);
$array[$i]["Machine_Name"] = $compmachine;
$array[$i]["Estimated_Start_Date"] = $CLT;
$prodhours = $array[$i]["Prod_Hrs"];
$array[$i]["Estimated_Completion_Date"] = date('Y-m-d H:i:s', strtotime($CLT . " +$prodhours hour"));
$array2[$compmachine] = $array[$i]["Estimated_Completion_Date"];
echo $array[$i]['Machine_Name'].'<br>';
echo $array[$i]['Estimated_Start_Date'].'<br>';
echo $array[$i]['Estimated_Completion_Date'].'<br>';
echo $array2[$compmachine].'<br>';
}
JobAssign(0,$Jobs_Data,$LT,$Machine_Interchange);
echo $Jobs_Data[0]['Machine_Name'].'<br>';
echo $Jobs_Data[0]['Estimated_Start_Date'].'<br>';
echo $Jobs_Data[0]['Estimated_Completion_Date'].'<br>';
echo $LT['Machine 3'];
Below is the output that I get.The first 4 lines of the output are from within the function and the next 4 are from outside the function.
Machine 3
2014-07-12 00:00:00
2014-07-15 11:00:00
2014-07-15 11:00:00
Machine 1
2014-07-30 00:00:00
2014-08-02 00:00:00
2014-07-15 11:00:00
When I echo the changed variables inside the function they do change but when I echo $arrayoutside of the function it does not change the values for $array. Only the values for $array2 have changed even though I have passed both arrays as reference in the function arguments. Which means that the line 4 and 8 are the same in the output which means that values for $array2 have changed but not for $array.

Answer 1

Try changing the variable $i on your for loop to another variable. Because it changes the value of the variable while it is looping.
function JobAssign($i,&$array,&$array2,$Machine_Interchange)
{
$compmachine = $array[$i]['Machine_Name'];
$CLT = $array[$i]["Estimated_Start_Date"];
$ET = $array[$i]["Estimated_Completion_Date"];
$Machine = $array[$i]['Machine_Name'];
$Compatibility_sql = "SELECT Machine2 FROM Machine_Interchange where Machine1 = '$Machine' and Value = 1";
$compatibility_query = mysql_query($Compatibility_sql) or die(mysql_error());
for($ii=0; $compatibility[$ii] = mysql_fetch_assoc($compatibility_query);$ii++);
array_pop($compatibility);
$maxkey = max(array_keys($compatibility));
$maxnumber = max(array_keys($array2))+1;
$k=0;
do{
$compmachine = $compatibility[$k]['Machine2'];
$CLT = $array2[$compmachine];
if($array2[$compatibility[$k]['Machine2']]>$array2[$compatibility[$k+1]['Machine2']])
{
$compmachine = $compatibility[$k+1]['Machine2'];
$CLT = $array2[$compatibility[$k+1]['Machine2']];
}
$k=$k+1;
}
while($k<$maxkey);
$array[$i]["Machine_Name"] = $compmachine;
$array[$i]["Estimated_Start_Date"] = $CLT;
$prodhours = $array[$i]["Prod_Hrs"];
$array[$i]["Estimated_Completion_Date"] = date('Y-m-d H:i:s', strtotime($CLT . " +$prodhours hour"));
$array2[$compmachine] = $array[$i]["Estimated_Completion_Date"];
echo $array[$i]['Machine_Name'].'<br>';
echo $array[$i]['Estimated_Start_Date'].'<br>';
echo $array[$i]['Estimated_Completion_Date'].'<br>';
echo $array2[$compmachine].'<br>';
}

Answer 2

The $array is changed as it should, the problem is that is changed in the wrong index.
Explanation:
You call the function with $i = 0 but $i is also used in the loop statement and exits the loop with a different value.
here is the line:
for($i=0; $compatibility[$i] = mysql_fetch_assoc($compatibility_query);$i++);
after the above $i is no longer 0 (as long as you have something to fetch)
So the index of $array that you echo inside the function is different from the index of $array you echo outside the function.
To fix your problem just change the variable of the above loop to something else, let's say $j:
for($j=0; $compatibility[$j] = mysql_fetch_assoc($compatibility_query);$j++);
so that no longer affects $i