如何验证PHP数组的结构？

Is there a function out there to make sure that any given array conforms to a particular structure? What I mean is that is has particular key names, perhaps particular types for values, and whatever nested structure.

Right now I have a place where I want to make sure that the array getting past has certain keys, a couple holding a certain data type, and one sub-array with particular key names. I've done a lot of run-around because I was passing malformed arrays to it, and finally I'm at the point where I have a bunch of

if ( ! isset($arr['key1']) ) { .... }
if ( ! isset($arr['key2']) ) { .... }
if ( ! isset($arr['key3']) ) { .... }

I would have saved a lot of time and consternation if I could have checked that the array conformed to a particular structure beforehand. Ideally something like

$arrModel = array(
    'key1' => NULL ,
    'key2' => int ,
    'key3' => array(
        'key1' => NULL ,
        'key2' => NULL ,
      ),
);

if ( ! validate_array( $arrModel, $arrCandidate ) ) { ... }

So, the question I'm asking is, does this already exists, or do I write this myself?

It doesn't exist built in.

Maybe try something like (untested):

array_diff(array_merge_recursive($arrCandidate, $arrModel), $arrModel)

I know this is sort of an old post, sorry if my answer is not approppriate.

I'm in the process of writing a php package that does exactly what you are asking for, it's called Structure.

What you can do with the package is something like:

$arrayCheck = new \Structure\ArrayS();
$arrayCheck->setFormat(array("profile"=>"array"));
if ($arrayCheck->check($myArray)) {
    //...
}

You can check it out here: http://github.com/3nr1c/structure

I came across a tool called Matchmaker on GitHub, which looks very comprehensive and has composer support and unit tests:
https://github.com/ptrofimov/matchmaker

You can include it into your project with composer require ptrofimov/matchmaker.

accepted answer make diff based on values, since it's about array structure you dont want to diff values. Insted you should use array_diff_key()

Function alone is not recursive. It will not work out of box on sample array from question.