PHP - foreach循环 - $ arr和＆$ value作为相同的变量

Question

foreach($foo as &$bar) {
  //do something
}

This is the syntax for a foreach loop in PHP. Usually, $foo & $bar are different variables, but my question is can they be the same variable? I'm asking if PHP will let me, not whether it is possible to write the code like that. I know this would modify the variable inside the loop, and I'm not worried about that.

Answer 1

It will work, ONCE, but only because of a quirk in PHP:

php > $x = array(1,2,3);
php > foreach($x as $x) { echo $x; }
123
php > var_dump($x);
int(3)

Note that the loop actually ran for all 3 values of the original $x array, but after the loop exits, $x, is now a mere int - it's no longer an array.

This holds true if the as $x is a straight plain $x variable, or a &$x reference.