<?php
$list = array("key1"=>3,"key2"=>5,"key3","key4"=>2);
foreach($list as $key=> $value)
{
{
$list[$value] = 1;
}
}
echo "<pre>";
PD9waHAKCiRsaXN0ID0gYXJyYXkoImtleTEiPT4zLCJrZXkyIj0+NSwia2V5MyIsImtleTQiPT4yKTsKCmZvcmVhY2goJGxpc3QgYXMgJGtleT0+ICR2YWx1ZSkKewoJaWYoaXNfbnVtZXJpYygka2V5KSkKCXsKCQl1bnNldCgkbGlzdFska2V5XSk7CgkJJGxpc3RbJHZhbHVlXSA9IDE7Cgl9CgkKfQoKa3NvcnQoJGxpc3QpOwplY2hvICI8cHJlPiI7CnByaW50X3IoJGxpc3QpOw==