mt_getrandmax

max

Last updated: Fri, 14 Nov 2008

min

(PHP 4, PHP 5)

min — Znajduje najmniejszą wartość

Opis

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

mixed min ( array $liczby )

min() zwraca najmniejszą liczbę spośród podanych argumentów.

Jeśli pierwszym i jedynym argumentem funkcji jest tablica, zwrócona zostanie najmniejsza wartość z tej tablicy. Jeśli pierwszym argumentem jest liczba stałoprzecinkowa, ciąg znakowy lub liczba zmiennoprzecinkowa, należy podać przynajmniej dwa argumenty, a min() zwróci najmniejszy z nich. Można porównywać nieograniczoną ilość wartości.

Informacja: PHP będzie uznawał nieliczbowe wartości typu string jako 0, jednakże zwracany będzie ciąg znakowy, jesli zostanie on oznany numerycznie za najmniejszą wartość. Jeśli wiele argumentów zostanie uznanych za wartość 0, to min() zwróci wartość najmniejszą alfanumerycznie, jeśli zostały podane jakiekolwiek ciągi znakowe. W przeciwnym przypadku zwrócona zostanie wartość 0.

Example #1 Przykłady użycia min()


<?php
echo min(2, 3, 1, 6, 7);  // 1
echo min(array(2, 4, 5)); // 2
echo min(0, 'hello');     // 0
echo min('hello', 0);     // hello
echo min('hello', -1);    // -1

// W przypadku podania wielu tablic, min porównuje je od lewej do prawej, 
// A więc w poniższym przykładzie 2 == 2, ale 4 < 5
$val = min(array(2, 4, 8), array(2, 5, 1)); // array(2, 4, 8)

// Jeśli podane zostaną tablice i nie-tablice, nigdy nie jest zwracana
// tablica, jako że zawsze jest uznawana za element największy
$val = min('string', array(2, 5, 7), 42);   // string

?>

Patrz także: max() i count().

mt_getrandmax

max

Last updated: Fri, 14 Nov 2008

add a note User Contributed Notes
min

mlester at ndsuk dot com
12-Nov-2008 04:59


I have found a very useful trick to help get round the problem of setting a variable to max int when finding a min i.e.





<?php


$val = 10;


$min = 100000;  // This is unpleasant and I couldn't find a equivalent to the C++ MAXINT


if ($val < $min)


{


  $min = $val;


}


?>





try this ...





<?php


$dataSet = Array(7, 8, 9, -1, -100, 0, 1, 2, 3, 5, 6);


$min = true;


$max = true;


            


foreach ($dataSet as $data )


{


  echo("data = $data");


  $min = min($data, $min);


  $max = max($data, $max);


}


            


echo("min = $min");


echo("max = $max");


?>





$max can be set to anything e.g. "infinity", but the same trick doesn't work with min, however true does work (false doesn't). Not sure why though.





The above code even works with a data set like this...


<?php $dataSet = Array("0.5", 1, 2, "3", "-1", "5"); ?>





but min doesn't like null or negative float e.g. "-1.2" and "" can give some odd results too.

DO
03-Jul-2008 12:23


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 06:58


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
30-Jan-2008 02:43


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 05:11


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
14-Aug-2006 05:30


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 06:26


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 11:16


> 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 06:37


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 03:39


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
13-Jan-2005 02:16


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 04:43


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 11:30


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
19-Jul-2003 05:28


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 06:40


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



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

calin at php9 dot com
30-May-2003 05:19


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 11:36


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 08:47


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 08:36


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

add a note

mt_getrandmax

max

Last updated: Fri, 14 Nov 2008