寻找最大,最小和中等价值

I am working with user supplied dimensions on a variety of products. Users supplied the length, width and height, but to calculate shipping costs I have take the longest measurement and set it as length and add that to the girth, which is calculated by adding the two shorter measurements and multiplying them by 2.

$PackageSize = length + (width*2 + height*2)

I can find which value is the highest using:

$newlength=max($length, $width, $height); 

I can't figure out how to then figure out which are the two remaining values so I can plug them into the right place in the equation.

To me, the easiest way to do this is to leverage PHP's awesome array functions.

// create an array from the three dimensions
$sizes = array( $length, $width, $height );
// sorts the values from smallest to largest
sort( $sizes );
// assigns the sorted values to the variables width, height, length
list( $width, $height, $length ) = $sizes;

// Now, $length is the longest dimension, $width is shortest, and $height is the middle value

Why don't you sort? For example (if the values are numerical)

 $values = [$length, $width, $height];
 rsort($values);
 $PackageSize = $values[0] + ($values[1]*2 + $values[2]*2);

Put the values into an array and sort the array. Then you can access them in order of value

$dimens = [$length, $width, $height]
rsort($dimens)
$dimens[0] // Is largest
$dimens[1] // Is next
$dimens[2] // Is smallest

You can put them in an array and sort it.

$length = 10;
$width = 7; 
$height = 9;

$array = [$length,$width,$height];

Sort($array);

Echo "largest: " . $array[2] ."
";
Echo "the other two " . $array[1] . " " . $array[0]

https://3v4l.org/PmdZu