数组索引是否可以从同一数组中的其他数组索引获取值

Question

The question is "can an array index get value from other array index in the same array?" Such as when you have an array variable like this:

$conf = [
  "app" => [
    "name" => "myApplicationName",
    "key" => md5($conf['app']['name']) // I mean to call itsself
    // I tried using $this but return into error

  ]
]

When I write $conf['app']['name'] it returns the error:

Undefined variable: conf in..

So can I call or get value to an array index from other array index in the same array?

Answer 1

As you've seen, because of the way PHP parses the array for definition, that syntax does not work. You can define them separately:

$conf["app"]["name"] = "myApplicationName";
$conf["app"]["key"]  = md5($conf['app']['name']);

Or define the large array and add it:

$conf = [
  "app" => [
    "name" => "myApplicationName",
    "something" => "something"
    //add more keys etc...
  ]
];
$conf["app"]["key"] = md5($conf['app']['name']);