Related questions about the _set

Questions about the __set

Class aa{
function __set ($pro, $v) {
echo "a\n";
$this->pro= $v;
echo "$v \ n";
}
}

$a =new AA;
$a->b=1;

The output is a a 1 1;

2 questions, why output 2 times;

Why is a a 1 1 instead of a 1 a 1;


------to solve the idea----------------------
You put echo "a\n"; Change to echo "$pro \ n"; You'll see
b because the B attribute does not exist, it enters the __set method
Pro also because the Pro attribute does not exist, enter the __set method again
1 Enter two times, print two times the value is not surprising.
1

When $this->pro= $v;
instead $this $pro = $v;
It's only once.

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