mt_getrandmax

max

Last updated: Sun, 25 Nov 2007

min

(PHP 4, PHP 5)

min — Εύρεση της μικρότερης τιμής

Περιγραφή

number min ( number $arg1 , number $arg2 [, $... ] )

number min ( array $numbers )

Η min() επιστρέφει την αριθμητικά μικρότερη από της τιμές των παραμέτρων.

Στην πρώτη περίπτωση, χρειάζεστε τουλάχιστον δύο παραμέτρους και η min() επιστρέφει τη μικρότερη των τιμών. Μπορείτε να συγκρίνετε απεριόριστο πλήθος τιμών. Εάν μία από τις μεταβλητές δεν είναι ορισμένη, η min() θα αποτύχει.

Στη δεύτερη περίπτωση, η min() επιστρέφει την μικρότερη τιμή στο numbers .

Εάν μία ή περισσότερες τιμές είναι float, όλες οι τιμές θα αντιμετωπισθούν ως floats, και θα επιστραφεί ένας float. Εάν δεν υπάρχει τιμή που να είναι float, όλες αντιμετωπίζονται ως integers, και θα επιστραφεί ένας integer. Σε περίπτωση αποτυχίας, η min() επιστρέφει NULL και ένα error of level E_WARNING θα παραχθεί.

<?php
$a = 4;	
$b = 9; 
$c = 3;
$arr = array(99, 34, 11);

// You may want to implement your own error checking in 
// case of failure (a variable may not be set)
if (!$min_value = @min($a, $b, $c)) {
    echo "Could not get min value, please try again.";
} else {
    echo "min value is $min_value";
}

print min($arr);  // 11

?>

Αατρέξτε επίσης στη max().

mt_getrandmax

max

Last updated: Sun, 25 Nov 2007

add a note User Contributed Notes
min

DO
03-Jul-2008 03:23


I've modified the bugfree min-version to ignore NULL values (else it returns 0).





<?php


function min_mod () {


  $args = func_get_args();


 


  if (!count($args[0])) return false;


  else {


    $min = false;


    foreach ($args[0] AS $value) {


      if (is_numeric($value)) {


        $curval = floatval($value);


        if ($curval < $min || $min === false) $min = $curval;


      }


    }


  }


 


  return $min;   


}


?>

harmor
21-Feb-2008 09:58


A way to bound a integer between two values is:



function bound($x, $min, $max)

{

     return min(max($x, $min), $max);

}



which is the same as:



$tmp = $x;

if($tmp < $min)

{

    $tmp = $min;

}

if($tmp > $max)

{

     $tmp = $max;

}

$y = $tmp;



So if you wanted to bound an integer between 1 and 12 for example:



Input:

$x = 0;

echo bound(0, 1, 12).'<br />';

$x = 1;

echo bound($x, 1, 12).'<br />';

$x = 6;

echo bound($x, 1, 12).'<br />';

$x = 12;

echo bound($x, 1, 12).'<br />';

$x = 13;

echo bound($x, 1, 12).'<br />';



Output:

1

1

6

12

12

johngreenbury at australianescapes dot com dot au
29-Jan-2008 05:43


You will get an "Wrong parameter count" error (PHP 4 and possibly 5) if your array looks like the following:



min(115.23,432.11,0.00,45.76)



The 0.00 creates the error. Convert the 0.00 to a high number such as 10000000000.00 or remove it from the array before running the min() function.

piotr_sobolewski at o2 dot nospampleasenono dot pl
07-Nov-2007 08:11


Be very careful when your array contains both strings and numbers. This code works strange (even though explainable) way:

var_dump(max('25.1.1', '222', '99'));

var_dump(max('2.1.1', '222', '99'));

dave at dtracorp dot com
13-Aug-2006 08:30


empty strings '' will also return false or 0, so if you have something like



$test = array('', 1, 5, 8, 44, 22);



'' will be returned as the lowest value



if you only want to get the lowest number, you'll have to resort to the old fashioned loop



// default minimum value

$minVal = 100;

foreach ($test as $value) {

if (is_numeric($value) && $value < $minVal) {

$minVal = $value;

}

johnphayes at gmail dot com
02-May-2006 09:26


Regarding boolean parameters in min() and max():



(a) If any of your parameters is boolean, max and min will cast the rest of them to boolean to do the comparison.

(b) true > false

(c) However, max and min will return the actual parameter value that wins the comparison (not the cast).



Here's some test cases to illustrate:



1.  max(true,100)=true

2.  max(true,0)=true

3.  max(100,true)=100

4.  max(false,100)=100

5.  max(100,false)=100

6.  min(true,100)=true

7.  min(true,0)=0

8.  min(100,true)=100

9.  min(false,100)=false

10. min(100,false)=false

11. min(true,false)=false

12. max(true,false)=true

steffen at morkland dot com
16-Mar-2006 02:16


> NEVER EVER use this function with boolean variables !!!

> Or you'll get something like this: min(true, 1, -2) == true;



> Just because of:

> min(true, 1, -2) == min(min(true,1), -2) == min(true, -2) == true;



It is possible to use it with booleans, there is is just one thing, which you need to keep in mind, when evaluating using the non strict comparison (==) anyting that is not bool false, 0 or NULL is consideret true eg.:

(5 == true) = true;

(0 == true) = false;

true is also actually anything else then 0, false and null. However when true is converted to a string or interger true == 1, therefore when sorting true = 1. But if true is the maximum number bool true is returned. so to be sure, if you only want to match if true is the max number remember to use the strict comparison operater ===

31-Jan-2006 09:37


NEVER EVER use this function with boolean variables !!!

Or you'll get something like this: min(true, 1, -2) == true;



Just because of:

min(true, 1, -2) == min(min(true,1), -2) == min(true, -2) == true;



You are warned !

DASPRiD � d [AT] sprid [DOT] de
06-Jul-2005 06:39


Here is my slightly modified version of the bugfree min-version. Now the max() function is no longer used in the modification and overall it's fasten up. Would be nice to get some feedback.



<?php

function min_mod () {

  $args = func_get_args();

  

  if (!count($args)) return false;

  else {

    $min = false;

    foreach ($args AS $value) {

      $curval = floatval($value);

      if ($curval < $min || $min === false) $min = $curval;

    }

  }

  

  return $min;    

}

?>

alx5000 at walla dot com
12-Jan-2005 05:16


If you want min to return zero (0) when comparing to a string, try this:



<?php

min(3,4,";");  // ";"

min(0,min(3,4,";")) // 0

?>

nonick AT 8027 DOT org
24-Jan-2004 07:43


I tested this with max(), but I suppose it applies to min() too: If you are working with numbers, then you can use:

 

    $a = ($b < $c) ? $b : $c;

 

 which is somewhat faster (roughly 16%) than

 

    $a = min($b, $c);

 

 I tested this on several loops using integers and floats, over 1 million iterations.

 

 I'm running PHP 4.3.1 as a module for Apache 1.3.27.

browne at bee why you dot ee dee you
16-Dec-2003 02:30


min() can be used to cap values at a specific value. For instance, if you're grading papers and someone has some extra credit, but  that shouldn't make it to the final score:



$pts_possible = 50;

$score = 55;



// Percent will equal 1 if $score/$pts_possible is greater than 1

$percent = min($score/$pts_possible,1);

kieran at mgpenguin dot net
18-Jul-2003 08:28


Further modifications to the minnum function above.. This is for a project where I had to grab an entire column out of a database consisting of values that might be string, might be string representations of numbers (floating point or integer) or might be NULL, and find the minimum NUMERIC value:



function minnum($numarray){

    //dont use min(), it contains a bug!

    $min=0;

    if ( ! is_array($numarray) ) $numarray = func_get_args();

    if(is_array($numarray)==true){

        $min=max($numarray);

        for($z=0;$z<count($numarray);$z++){

            $curval=floatval($numarray[$z]);

            if(($curval != 0) && ($curval < $min)){

                $min=$curval;

            }

        }

    }

    return $min;

}



Gets the floating point value of each entry and uses this to check whether it's actually a number before checking whether it's the minimum or not. Also contains modifications noted above to use it as a drop in replacement for min - ie multiple values passed.

Merome at wanadoo dot fr
05-Jul-2003 09:40


Caution : it seems that min() can return a string : 



min(";",50)=";" (I expected zero)

calin at php9 dot com
30-May-2003 08:19


if you have an array like this



$arSrc[0]=14;

$arSrc[1]=16;

$arSrc[2]=13;

$arSrc[3]=17;



then in order to get the min element and its position in the array you can do:



$iMinValue = min($arSrc);

$arFlip = array_flip($arSrc);

$iMinPosition = $arFlip[$iMinValue];



echo 

 '<br />min_value=',

 $iMinValue,

 '<br />min_position=',

 $iMinPosition

;



this example works for also for an associative array; of course with numeric values

08-Jul-2002 02:36


Re: above example - for a proper drop in replacement for the above, insert



if ( ! is_array($numarray) )

   $numarray = func_get_args();



after

   $min=0;



(For PHP3, check 

if (intval(PHP_VERSION) >= 4 && ! is_array($numarray)) 

   $numarray = func_get_args();

)

kevin at pricetrak dot com
08-Apr-2002 11:47


The 'undefined' behaviour can bit you badly. I would expect min(undefined, -1000) to return -1000. Not so.

nak2 at mail2000 dot ru
14-Mar-2002 11:36


If one of elements is undefided, min() result is underfinded too

add a note

mt_getrandmax

max

Last updated: Sun, 25 Nov 2007