替换foreach循环中的数组值

Question

What am I doing wrong here? It's so simple and I'm overlooking something. I'm trying to replace the value of an array key within a foreach loop:

$arr = array();
$arr['firstimg'] = '123';
$arr['secondimg'] = '456';
$arr['thirdimg'] = '789';

foreach ($arr as $key => $value) {

    if ($key == 'secondimg') { 
      $value = '000';

    } 

}

print_r($arr);

The array is staying the same.

Answer 1

The variable $value is scoped to the loop. You need to update the value of $arr[$key].

Alternatively you can declare the loop as follows:

foreach ($arr as $key => &$value) {

This makes $value a reference to the original array value (rather than a copy).