Question

I have the code below. I want to change $b to use it again with values. If I do so it changes $a as well. How can I assign a value to $b again after previously assigning it as a reference to $a?

$a = 1;
$b = &$a;

// later
$b = null;

Answer 1

See explanation inline

$a = 1;    // Initialize it

$b = &$a;  // Now $b and $a becomes same variable with 
           // just 2 different names  

unset($b); // $b name is gone, vanished from the context.
           //  But $a is still available

$b = 2;    // Now $b is just like a new variable with a new value.
           // Starting a new life.