How to check if an integer is within a range of numbers in PHP?

Question

How can I check if a given number is within a range of numbers?

Answer 1

Here is my little contribution:

function inRange($number) {
  $ranges = [0, 13, 17, 24, 34, 44, 54, 65, 200];
  $n = count($ranges);

  while($n--){
    if( $number > $ranges[$n] )
      return $ranges[$n]+1 .'-'. $ranges[$n + 1];
  }

Answer 2

function limit_range($num, $min, $max)
{
  // Now limit it
  return $num>$max?$max:$num<$min?$min:$num;
}

$min = 0;  // Minimum number can be
$max = 4;  // Maximum number can be
$num = 10;  // Your number
// Number returned is limited to be minimum 0 and maximum 4
echo limit_range($num, $min, $max); // return 4
$num = 2;
echo limit_range($num, $min, $max); // return 2
$num = -1;
echo limit_range($num, $min, $max); // return 0

Answer 3

Another way to do this with simple if/else range. For ex:

$watermarkSize = 0;

if (($originalImageWidth >= 0) && ($originalImageWidth <= 640)) {
    $watermarkSize = 10;
} else if (($originalImageWidth >= 641) && ($originalImageWidth <= 1024)) {
    $watermarkSize = 25;
} else if (($originalImageWidth >= 1025) && ($originalImageWidth <= 2048)) {
    $watermarkSize = 50;
} else if (($originalImageWidth >= 2049) && ($originalImageWidth <= 4096)) {
    $watermarkSize = 100;
} else {
    $watermarkSize = 200;
}

Answer 4

The expression:

 ($min <= $value) && ($value <= $max)

will be true if $value is between $min and $max, inclusively

See the PHP docs for more on comparison operators

Answer 5

Some other possibilities:

if (in_array($value, range($min, $max), true)) {
    echo "You can be sure that $min <= $value <= $max";
}

Or:

if ($value === min(max($value, $min), $max)) {
    echo "You can be sure that $min <= $value <= $max";
}

Actually this is what is use to cast a value which is out of the range to the closest end of it.

$value = min(max($value, $min), $max);

Example

/**
 * This is un-sanitized user input.
 */
$posts_per_page = 999;

/**
 * Sanitize $posts_per_page.
 */
$posts_per_page = min(max($posts_per_page, 5), 30);

/**
 * Use.
 */
var_dump($posts_per_page); // Output: int(30)

Answer 6

You can use filter_var

filter_var(
    $yourInteger, 
    FILTER_VALIDATE_INT, 
    array(
        'options' => array(
            'min_range' => $min, 
            'max_range' => $max
        )
    )
);

This will also allow you to specify whether you want to allow octal and hex notation of integers. Note that the function is type-safe. 5.5 is not an integer but a float and will not validate.

Detailed tutorial about filtering data with PHP:

• https://phpro.org/tutorials/Filtering-Data-with-PHP.html