Example:
$a[] = '56';
$a[] = '66';
$a[] = '';
$a[] = '58';
$a[] = '85';
$a[] = '';
$a[] = '';
$a[] = '76';
$a[] = '';
$a[] = '57';
Actually how to find average value from this array excluding empty. please help to resolve this problem.
4 Answers
first you need to remove empty values, otherwise average will be not accurate.
so
$a = array_filter($a);
$average = array_sum($a)/count($a);
echo $average;
More concise and recommended way
$a = array_filter($a);
if(count($a)) {
echo $average = array_sum($a)/count($a);
}
5 Comments
Shane N
Keep in mind that you should first check to ensure count() is positive, otherwise you'll get a divide by zero error
Milo LaMar
array_filter would remove zeros also, skewing the average.
Mubin
@MiloLaMar: yes, for that please check Don't Panic's answer below.
Oleg
You should make
count check AFTER you've filtered out empty values
Ismael Miguel
The double use of the
count() an add some needless overhead from calling count() multiple times. You can either do $count = count($a); or just do if($a). Both are good enough solutions. I would use if($a) which saves on calling count() on empty arrays, but is harder to understand for those starting to learn the language.The accepted answer works for the example values, but in general simply using array_filter($a) is probably not a good idea, because it will filter out any actual zero values as well as zero length strings.
Even '0' evaluates to false, so you should use a filter that explicitly excludes zero length strings.
$a = array_filter($a, function($x) { return $x !== ''; });
$average = array_sum($a) / count($a);
1 Comment
Ismael Miguel
With PHP 7.4+, you can do
array_filter($a, fn($x)=>$x !== '');, using the syntax for arrow function.echo array_sum($a) / count(array_filter($a));
1 Comment
JimL
you need to do count(array_filter($a)) in order to not include the empty values.
As a late look, item controls should be done with numeric check. Otherwise something like this $array = [1.2, 0.33, [123]] will corrupt the calculation:
// Get numerics only.
$array = array_filter($array, fn($v) => is_numeric($v));
// Get numerics only where value > 0.
$array = array_filter($array, fn($v) => is_numeric($v) && ($v > 0));
Finally:
public static function average(array $array, bool $includeEmpties = true): float
{
$array = array_filter($array, fn($v) => (
$includeEmpties ? is_numeric($v) : is_numeric($v) && ($v > 0)
));
return array_sum($array) / count($array);
}
Credits: froq.util.Arrays
$a[] = '56';it should be$a[] = 56;