如何检查数组在 PHP 中的未指定索引处是否有空值？

Question

How can I check if any of the arrays contains empty fields (they are both dynamic arrays so the empty value can be in any index in both of them)?

Array1 ( [0] => dfsg [1] => dfasg [2] => d5g [3] => )
Array2 ( [0] => d54fgv [1] => [2] => df4g4 [3] => d645 )

It would be good to know at which index as well, otherwise, just to know if there is any empty fields.

Answer 1

There are many ways to achieve this. One that springs to mind is checking if the count of a filtered version is lesser than the original array. You can even customize this to specify which sort of filter-values you are looking for by supplying a closure to array_filter() .

if (count(array_filter($a1)) < count($a1)) {
    echo '$a1 has at least one empty value';
}

From the manual of array_filter() ,

If no callback is supplied, all entries of array equal to FALSE (see converting to boolean ) will be removed.

• Live demo at https://3v4l.org/dkGPr .
• Documentation for array_filter

If you need to know which index(es) is empty, you can check the difference of the filtered array with the original array through array_diff() . You can then use array_keys() on the filtered array to obtain all the indexes.

• Live demo at https://3v4l.org/oN8QR
• Documentation for array_diff