The expression $ids of type string|array|null is not guaranteed to be traversable. How about adding an additional type check?
There are different options of fixing this problem.
If you want to be on the safe side, you can add an additional type-check:
$collection=json_decode($data,true);if(!is_array($collection)){thrownew\RuntimeException('$collection must be an array.');}foreach($collectionas$item){/** ... */}
If you are sure that the expression is traversable, you might want to add a
doc comment cast to improve IDE auto-completion and static analysis:
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: