Larry Garfield has a new post to his site sharing a method for short and safe array iteration based on a "neat trick" he picked up reading a mailing list.

PHP's largely loose, dynamic typing has plenty of both pros and cons. One con in particular is that you don't always know for sure if a value you're trying to use has been set yet, or is non-null. PHP will dutifully whine at you if you try to use a null value, sometimes fatally. (Yet another reason to structure your code to avoid nulls, period.)

One place this comes up in particular is in foreach() loops, especially when working with nested array structures. (PHP lacks a struct type, but makes anonymous hash maps so easy that they get used as the uber data type, for better or worse.)

He gives an example of looping through a dataset with a foreach where the array index reference is used to reference the source array. While you could always wrap the loop in an if statement to check first, he has another interesting method to do the same thing. With the help of the null-coalesce operator (??) in PHP 7, you can essentially say: "if the array index referenced is null/does not exist, use an empty set". Check out the rest of the post for code examples putting this method to use.