In PHP, how can I correct missing keys in an array?

for ($i = 0; $i < $loopSize; $i++)
{
process($myArray[$i]);
}

foreach($myArray as $key=> $value)
{
    process($value);
    /** or process($myArray[$key]); */
}

or even more simply


foreach($myArray as $value)
{
    process($value);
}

foreach($myArray as $key=>$val)
{
     myArray[$key] = myFunction(myArray[$key]);
}

$a = getA(); $b = getB();
foreach($a as $key=>val)
{
    $sql = "INSERT INTO table (field1, field2) VALUES ($a[$key], $b[$key])";
}