我是否需要在PHP中初始化多维数组的每个键？

Question

stricly speaking / best practice: do I need to set up every 'deeper nested sub array' or can you just access it?

//so do I need to do this:
if(!isset($multiArray[$newKey])) $multiArray[$newKey] = array();

//before I can do this?
$multiArray[$newKey][] = 'somevalue';

Answer 1

Strictly speaking no, PHP will create the new array before pushing the value to it, without any problem.

Best practice? It's probably personal opinion based, I would say create the array first for readability and it makes sense logically. If another developer picks up your code, it might not be obvious that you are creating a new array, as opposed to pushing to an existing array.