CODEWITHSUNDEEP
php
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Reputation: 11255

Verifying all Keys in an Array

Currently, this is what I do to check if all keys of an array $A are within a subset of another array $B.

$B = array('a', 'b', 'c', 'd');

if(array_keys($A) == array_intersect(array_keys($A), $B))
{
 action if true
}

I am wondering if there is a more straight forward way of doing this, something like the in_array() function.

Usage Example:

Checking the $_POST array to ensure that all keys matches a dynamic form and filter out extra keys if the form is hacked.

Upvotes: 0

Views: 129

Answers (3)

Viktor
Viktor

Reputation: 3536

Not perhaps that straight forward to read, but this comment in the PHP manual for array_intersect provides a compact way of checking whether an array is a subset of another.

if (array_unique(array_keys($a) + $b) == $b)
{
    echo 'valid array keys';
}

Test example

Upvotes: 1

deceze
deceze

Reputation: 522085

if (array_diff_key($A, array_flip($B))) {
    // there are keys in $A that are *not* in $B!
}

or possibly:

if (array_diff_key(array_flip($B), $A)) {
    // not all of the keys in $B are in $A!
}

Upvotes: 2

Madara's Ghost
Madara's Ghost

Reputation: 174957

No, your way is probably the same way I would have used. If you need to compare against a list, an array is the best solution. Though I would have probably used array_intersect_keys_ instead.

Upvotes: 0

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