CODEWITHSUNDEEP
phparray-filter
davidlee
davidlee

Reputation: 6177

error in array_filter

I have an issue here with filter_array.

below is my code:

$array = array("0","0","1");
function returnzero($d){

    if($d=='0'){
       return $d;
    }
}

$all_zeros = array_filter($array, "returnzero");
echo count($all_zeros);

I would like to filter out all values that none other than zero. Above is my code. However, the count result returned is always 0.

may I know what is my mistake?

Thanks.

Upvotes: 2

Views: 1162

Answers (5)

Marc B
Marc B

Reputation: 360802

The function you pass into array_filter() must return TRUE or FALSE to tell PHP whether the current value being checked matches what you're filtering for. You're returning the number that was passed in. Since you're checking for zeroes, you're returning zero, which PHP interprets as FALSE. You could rewrite the function as follows:

if ($d == 0) {
    return TRUE;
} else {
    return FALSE;
}

or more concisely

return ($d == 0);

Upvotes: 0

rubber boots
rubber boots

Reputation: 15204

Modify the return value to reflect the purpose:

 function iszero($d) { return $d == '0'; }

 $all_zeros = array_filter($array, 'iszero');

Regards

rbo

Upvotes: 0

Alex Pliutau
Alex Pliutau

Reputation: 21937

Function must returns TRUE. 

    $array = array(0, 0, 1);
    function returnzero($d){

        if($d=='0'){
           return true;
        }
    }

    $all_zeros = array_filter($array, "returnzero");
    echo count ($all_zeros);

Upvotes: 1

ircmaxell
ircmaxell

Reputation: 165271

See the documentation on array_filter

You need to be returning true or false, not the number... So your function becomes:

function returnzero($d) { return $d == 0; }

Upvotes: 2

Gazler
Gazler

Reputation: 84180

You need to check $d != 0 and it will return all the non-zero values. Trying to return 0 is the same as returning false, so it fails.

Upvotes: 1

Related Questions