log
This code loops through seven arrays and finds the highest average value within those arrays - and changes the font color for it. Great for highlighting.
The biggest take-away is this the row
if($average[$i] == max($average))
The number_format just rounds the numbers to 0 decimal points.
<?php
for ( $i = 0; $i <= 6; $i++) {
$num = $i+1;
if($average[$i] == max($average)) {
echo "Value ".$num.": <font color='red'>".number_format($average[$i], 0, '.', '')." % </font<br>";
} else {
echo "Value ".$num.": ".number_format($average[$i],0,'.','')." %<br>";
}
}
?>
### OUTPUT
Value 1: 52 %
Value 2: 58 %
Value 3: 56 %
Value 4: 73 %
Value 5: 77 % <- this 77 is highlighted in red
Value 6: 71 %
Value 7: 75 %
max
(PHP 4, PHP 5)
max — Znajduje największą liczbę
Opis
max() zwraca największą liczbę spośród podanych argumentów.
Jeśli pierwszym i jedynym argumentem jest tablica, max() zwróci największą liczbę z tej tablicy. Jeśli pierwszy argument jest liczbą całkowitą, zmiennoprzecinkową czy łańcuchem znaków, musisz mieć conajmniej dwa argumenty, spomiędzy których funkcja max() zwróci największą wartość. Za pomocą tej funkcji można porównywać nieograniczoną ilość liczb.
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 max()
<?php
echo max(1, 3, 5, 6, 7); // 7
echo max(array(2, 4, 5)); // 5
echo max(0, 'hello'); // 0
echo max('hello', 0); // hello
echo max(-1, 'hello'); // hello
// W przypadku podania wielu tablic, min porównuje je od lewej do prawej,
// A więc w poniższym przykładzie 2 == 2, ale 4 < 5
$val = max(array(2, 4, 8), array(2, 5, 7)); // array(2, 5, 7)
// Jeśli podane zostaną tablice i nie-tablice, zawsze zwracana jest
// tablica, jako że zawsze jest uznawana za element największy
$val = max('string', array(2, 5, 7), 42); // array(2, 5, 7)
?>
add a note
User Contributed Notesmax
Marcus Zacco
29-Sep-2008 06:47
29-Sep-2008 06:47
henk at tobbe dot net dot au
16-Apr-2008 09:05
16-Apr-2008 09:05
In a publication by WROX I noted a variant of the earlier "bound" function:
A parameter had to be between 1 and 3...
$par=round((min(max($x,1),3));
stuff at necr0manzer dot de
03-Mar-2008 08:11
03-Mar-2008 08:11
mick at wireframe dot com's solution to finding the key for the highest value didn't work for me, so I wrote one myself:
<?php
function max_key($array) {
foreach ($array as $key => $val) {
if ($val == max($array)) return $key;
}
}
$array = array(1, 2, 5, 7, 4);
echo max($array); // 7
echo max_key($array); // 3
?>
of course this also works with associative arrays, but it will only return a single result!
harmor
21-Feb-2008 06:56
21-Feb-2008 06:56
A way to bound a integer between two values is:
function bound($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
mick at wireframe dot com
31-Oct-2007 12:51
31-Oct-2007 12:51
There are a couple of things you can do for cleaner code if you want the keys returned from the array. I am not sure how they each impact performance, but the visual readability is more beneficial for me -- your mileage may vary.
In the first example keys and max value is returned:
<?php
// First, let's pretend we have an array like this:
$Some_Array = array(
'john' => 40,
'susan' => 40,
'jane' => 24,
'michael' => 19,
'jimmy' => 38
);
function max_extract($My_Array) {
$Max_Value = max($My_Array);
return array_fill_keys(array_keys($My_Array, $Max_Value), $Max_Value);
} // ! max_extract()
?>
Or, if you are only interested in the keys and don't care what the max is:
<?php
function max_extract($My_Array) {
return array_keys($My_Array, max($My_Array));
// You can also array_flip() this is you want them as keys
// or if some other reason makes this relevant/needed.
} // ! max_extract()
?>
There are many possible variations when using the search parameter of array_keys() along with other array functions.
sta
07-Sep-2007 06:05
07-Sep-2007 06:05
Or to take multiple maximum values into consideration:
function doublemax($mylist){
$maxvalue=max($mylist);
$max_keys = array();
while(list($key,$value)=each($mylist)){
if($value==$maxvalue)
array_push($max_keys,$key);
}
return $max_keys;
}
joan dot codina at upf dot edu
14-Jul-2007 07:11
14-Jul-2007 07:11
This is highly ineficient, but can be a bit better
<?
function doublemax($mylist){
$maxvalue=max($mylist);
while(list($key,$value)=each($mylist)){
if($value==$maxvalue)
return array("key"=>$key,"value"=>$value);
}
}
?>
michaelangel0 at mail.com
05-Jul-2007 12:00
05-Jul-2007 12:00
Matlab users and others may feel lonely without the double argument output from min and max functions.
To have the INDEX of the highest value in an array, as well as the value itself, use the following, or a derivative:
<?
function doublemax($mylist){
$maxvalue=max($mylist);
while(list($key,$value)=each($mylist)){
if($value==$maxvalue)$maxindex=$key;
}
return array("m"=>$maxvalue,"i"=>$maxindex);
}
?>
jeremi23 at gmail dot com
14-Jun-2007 12:09
14-Jun-2007 12:09
max on a an array with key/values
<?
$tmp = array(1 => 5, 2=> 3);
echo max($tmp);
?>
this return 5, so the max is done on the values.
johnmott59 at hotmail dot com
17-May-2007 09:35
17-May-2007 09:35
To find the maximum value from a set of 1-dimensional arrays, do this:
$d1 = array(450,420,440,430,421);
$d2 = array(460,410,410,430,413,375,256,411,656);
$d3 = array(430,440,470,435,434,255,198);
$t = max(max($d1),max($d2),max($d3));
// $t is 656
The inner max() functions operate on the arrays, the outer max compares the numeric results of the inner ones.
johnphayes at gmail dot com
02-May-2006 06:27
02-May-2006 06:27
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
tim at (NOSPAM) dot crazynot2 dot com
08-Nov-2005 10:56
08-Nov-2005 10:56
In response to the previous two posters (zher0 at netcarrier dot com & walkingmantis):
I was trying to do exactly what zher0 suggested; calculate the max value of a multi-dimensional array with variably sized 'sub-arrays'. Here is a simple little function I came up with to do just that:
<?php
function multimax( $array ) {
// use foreach to iterate over our input array.
foreach( $array as $value ) {
// check if $value is an array...
if( is_array($value) ) {
// ... $value is an array so recursively pass it into multimax() to
// determine it's highest value.
$subvalue = multimax($value);
// if the returned $subvalue is greater than our current highest value,
// set it as our $return value.
if( $subvalue > $return ) {
$return = $subvalue;
}
} elseif($value > $return) {
// ... $value is not an array so set the return variable if it's greater
// than our highest value so far.
$return = $value;
}
}
// return (what should be) the highest value from any dimension.
return $return;
}
?>
Please note that I have only performed very limited testing on this code -- be sure to check it thoroughly if you implement it somewhere!
nonick AT 8027 DOT org
17-Dec-2003 04:50
17-Dec-2003 04:50
If you are working with numbers, then you can use:
$a = ($b > $c) ? $b : $c;
which is somewhat faster (roughly 16%) than
$a = max($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.
mikhail_kovalev at mail dot ru
14-May-2003 01:32
14-May-2003 01:32
Note that in version 4.0.3 (the only version I tested):
max (0, 0); // returns 0.
max (0, false); // returns 0.
max (false, 0); // returns false.
max (false, false); // returns false.
As a solution use this:
(int) max (false, 0); // returns 0.
(int) max (false, false); // returns 0.