Check php array elements in specific range

Question

I can check if some integer value (which comes from user input, and thus should be filtered) is in specific range like this:

<?php
  $size=50;
  var_dump(in_array($size,range(1,100)));
?>

which will echo true if the size in range 1 to 100. Of course the other method is using filters:

<?php
  $size=50;
  $int_options = array("options"=>
                        array("min_range"=>0, "max_range"=>256));
  var_dump(filter_var($size, FILTER_VALIDATE_INT, $int_options));
?>

But, what if I need to know if the elements of an array are in this range?(and probably remove those not) What is the best practice, considering the performance and memory usage. I prefer to use php functions instead of writing mine.

do you want to compare each array element to be in different range? — user1646111
– user1646111, Commented Jul 23, 2013 at 10:32
No! All elements should be checked to be in dedicated range for example 1 to 100 and ofcource I prefer the method in which data is sanitized and filtered, because the $size comes form user input. thanks — Peyman Mohamadpour
– Peyman Mohamadpour, Commented Jul 23, 2013 at 10:35

nothrow · Accepted Answer · 2013-07-23 10:34:52Z

3

Slightly functional approach (I don't know if PHP support lambdas):

function mapper($n) { return $n >= 1 && $n <= 100 ? 1 : 0; }

...

if (array_product(array_map('mapper', $array)) == 1) { }

Not very performance nor memory efficient, though.

For removing, I'd suggest using array_filter.

function my_filter($n) { return $n >= 1 && $n <= 100; }

...

$newarray = array_filter($array, 'my_filter');

(btw, who the hell designed that language.. array_map and array_filter have different order of parameters?!)

answered Jul 23, 2013 at 10:34

nothrow

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3 Comments

Raptor Over a year ago

sidenote: since PHP is originated from different language, they have different orders. Other example is in_array() and strpos(). Even crazier, order of arguments in some functions can be reversed, e.g. implode()

Peyman Mohamadpour Over a year ago

Thanks but that looks too expensive. I'd love some more compressed way. I have 50 of this arrays in my page

nothrow Over a year ago

@Arash, and the second one? (array_filter). That should be cheap.

Raptor · Accepted Answer · 2013-07-23 10:30:47Z

0

If I were you, I will use a more simple approach:

$size=50;
if($size <= 100 && $size >= 1) {
  return true;
} else {
  return false;
}

No function call, simple integer comparison. Good performance.

answered Jul 23, 2013 at 10:30

Raptor

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2 Comments

Peyman Mohamadpour Over a year ago

Thanks man but this is not my question. the question is related to array elements, and that was just the begining. As the $size comes from user input, it should be sanitized and so I prefered to use those methods

Raptor Over a year ago

you can wrap the comparison codes into a small function, and call the function for each of your array elements.

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