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array_udiff_assoc> <array_splice
[edit] Last updated: Fri, 24 Jul 2009

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array_sum

(PHP 4 >= 4.0.4, PHP 5)

array_sum배열 값들의 합을 계산

설명

number array_sum ( array $array )

array_sum()은 배열 값들의 합을 반환합니다.

인수

array

입력 배열.

반환값

값들의 합을 정수나 소수로 반환합니다.

변경점

버전 설명
4.2.1 PHP 4.2.1 이전 버전에서는 전달되는 배열 자체를 변경해서 문자열을 숫자로 변경했었다. (그 값에 따라 대부분 0으로 변환된다)

예제

Example #1 array_sum() 예제

<?php
$a 
= array(2468);
echo 
"sum(a) = " array_sum($a) . "\n";

$b = array("a" => 1.2"b" => 2.3,"c" => 3.4);
echo 
"sum(b) = " array_sum($b) . "\n";
?>

위 예제의 출력:

sum(a) = 20
sum(b) = 6.9



array_udiff_assoc> <array_splice
[edit] Last updated: Fri, 24 Jul 2009
 
add a note add a note User Contributed Notes array_sum
igz dot dwd dot 20 at gmail dot com 15-Oct-2011 08:32
As mysql_fetch_array returns associative and numeric indexes, you can simply use a flag.

<?php
$result
= mysql_query("SELECT id, name FROM mytable");
$row = mysql_fetch_array($result, MYSQL_NUM);
array_sum($row);
?>

Hope it helps.
davidcairngorm at gmail dot com 04-Sep-2011 09:07
If the array is a result from mysql_fetch_array, it contains every value twice and the sum will be double.
pligor at facebook dot com 02-Jun-2011 04:42
There was a case where I had a complex array, multi-dimesional and non-symmetric (not all elements of a sub-array were arrays themselves)
Although all the leaf elements of this array were numbers. In case you have two variables like that and you wanted to add all the values of the right variable to the left then you would need a function like below.

This is a recursive function which adds the values of two multidimensional arrays with the same key structure:

<?php
function multiDimArrayAdd(& $left, $right)    //created by George Pligor
{
    if(
is_array($left) && is_array($right))
    {
        foreach(
$left as $key => $val)
        {
            if(
is_array($val) )
            {
               
multiDimArrayAdd($left[$key], $right[$key]);
            }
           
$left[$key] += $right[$key];
        }
    }
}
?>
uhehesh at gmail dot com 07-Jan-2011 08:51
<?php
function avrg()
{
 
$count = func_num_args();
 
$args = func_get_args();
 return (
array_sum($args) / $count);
}
?>

This function calculates average of numbers given as arguments. Examples:
avrg(100, 200, 300) - returns 200.
avrg(5, 6) - returns 5.5.
avrg('foo') - returns 0.
Chris 18-Feb-2010 02:54
Average array values, ignoring zero values:

<?php
function array_average_nonzero($arr) {
   return
array_sum($arr) / count(array_filter($arr));
}
?>

<?php
$arr
= array(1,2,3,0,0);
echo
array_average_nonzero($arr); // returns 2
echo array_sum($arr) / count($arr); // returns 1.2
?>
hdeus at yahoo dot com 07-Oct-2008 12:31
Here is how you can multiply two arrays in the form of matrixes using a bit of matrix algebra (M*M).
By calling the function multiplyMatrix, you will be multiplying two sparse matrixes (zeros need not be included in the array for the operation to be performed).

<?php
$M
= array(
0=>array(1=>1,4=>1),
1=>array(2=>1,3=>1),
3=>array(1=>1),
4=>array(5=>1),
5=>array(6=>1)
);

$M1 = multiplyMatrix($M, $M); //multiplying $M by itself

echo '<pre>';print_r($M1);echo '</pre>';

function
multiplyMatrix($M1, $M2)
    {
#Helena F Deus, Oct 06, 2008
##Multiply two matrixes; $M1 and $M2 can be sparse matrixes, the indexes on both should match
       
if(is_file($M1)) {$matrix1 = unserialize(file_get_contents($M1));}
        else
$matrix1 = $M1;
       
           
       
#transpose M2
       
$M2t = transpose($M2);
       
        foreach (
$M2t as $row=>$tmp) {
           
##sum the result of the value in the col multiplied by the value in the vector on the corresponding row
               
               
foreach ($M1 as $row1=>$tmp1) {
                   
                   
$multiply[$row1] = array_rproduct($tmp,$tmp1);
                   
                    if(!
$multiply[$row1]){
                          exit;
                        }
                }
               
                foreach (
$multiply as $row1=>$vals) {
                   
                   
$sum[$row][$row1]=array_sum($vals);
                }
               
        }
   
   
$r=transpose($sum);
   
    return (
$r);
    }

function
transpose($M)
{
foreach (
$M as $row=>$cols) {
           
            foreach (
$cols as $col=>$value) {
                 if(
$value)
                
$Mt[$col][$row]=$value;
            }
        }
       
ksort($Mt);
       
return (
$Mt);           
}

function
array_rproduct($a1, $a2)
{
   
   
    foreach (
$a1 as $line=>$cols) {
       
$a3[$line] = $a1[$line]*$a2[$line];
        foreach (
$a2 as $line2=>$cols2) {
           
$a3[$line2] = $a1[$line2]*$a2[$line2];
        }
    }   
   
ksort($a3);
   
   
    return (
$a3);
   
   
}

?>
c dot heckemueller at befestigungsfuchs dot de 05-Sep-2008 06:00
<?php
/**
 * sum values in array
 *
 * @param array $arr
 * @param string [optional]$index
 * @return int result
 */
function array_sum_key( $arr, $index = null ){
    if(!
is_array( $arr ) || sizeof( $arr ) < 1){
        return
0;
    }
   
$ret = 0;
    foreach(
$arr as $id => $data ){
        if( isset(
$index )  ){
           
$ret += (isset( $data[$index] )) ? $data[$index] : 0;
        }else{
           
$ret += $data;
        }
    }
    return
$ret;
}
?>

With this function you can choose whether you sum specific keys in a multidim array, or a normalized array. it is designed to not trigger errors if a key is not set.
superman1101 28-Aug-2008 03:59
To elaborate on djyb2003 at yahoo dot fr. His function can be converted to recursive, but i've made a smaller function to do so:

<?php

 
function array_sum_all($array) {
  
$func = create_function("&\$arr=0,\$key=0","static \$a=0; if(is_int(\$arr)) { \$a+=\$arr; } return \$a;");
  
array_walk_recursive($array,$func);
   return
$func();
 }

$tab = array(
                
0 => array ("val1" => 2,"val2" => 5),
                
1 => array ("val1" => 6,"val2" => 10),
                
"toto" => array ("val1" => 15,"val2" => 50)
                );
var_dump(array_sum_all($tab)); //This will output: int(88);
?>

hope this helps someone
djyb2003 at yahoo dot fr 30-Jan-2008 01:01
here is a function that can sum values like these :

$tab = array(
                 0 => array ("val1" => 2,"val2" => 5)
                 1 => array ("val1" => 6,"val2" => 10)
                 "toto" => array ("val1" => 15,"val2" => 50)
                );

sum_subarrays_by_key( $tab, "val1" );

the function will sum all values with "val1" key in tab subarrays.

function sum_subarrays_by_key( $tab, $key ) {
       
        $sum = 0;
       
        foreach($tab as $sub_array) {
            $sum += $sub_array[$key];
        }
       
        return $sum;
       
    }

it can be transformed to be recursive and do also all depths possible in an array.

Hope it can be usefull!
Coder 17-Aug-2007 08:40
A much simpler algorithm for array_sub():

<?php
 
function array_sub($arr) {
    if (!
is_array($arr) || count($arr) == 0) {
      return
false;
    } else {
     
// get first element
     
$base = array_shift($arr);

      return
$base - array_sum($arr);
    }
  }
?>

This will return the exact same results that didikdwi's version.

However, didikdwi's result depends on knowing what the first value is. When this likely bug is removed, the code is:

<?php
 
function array_sub($arr){
   
$temp = array_sum($arr);
    return (
$temp !== false ? -$temp : false );
  }
?>
didikdwi at gmail dot com 18-Jul-2007 11:18
This is a simple approach to subtract array, both indexed and associative.

  function array_sub($arr) {
    if (!is_array($arr) || count($arr) == 0) {
      return false;
    } else {
      // get first element
      $base = array_shift($arr);

      if (count($arr) == 1) {
        // If only one element, return its
        return $base;
      }

      foreach ($arr as $val) {
        $base -= $val;
      }

      return $base;
    }
  }

// example
$arr1 = array(3, 2, 3);
echo array_sub($arr1);   // Output: -2
$arr2 = array(3.5, 2, 3);
echo array_sub($arr2);   // Output: -1.5
$arr3 = array('a' => 3, 'b' => 2, 'c' => 3);
echo array_sub($arr3);   // Output: -2
herenvardo at gmail dot com 25-Nov-2006 09:58
I'm not sure if something similar already exists, but I needed it so I made it:
<?php
 
/* Performs a pitagoric sum of the elements in $arr
   The pitagoric sum of a set of values is the square root of
   the sum of the sqare power of each value. So, for a, b, c
   it's sqrt(a^2 + b^2 + c^2) */
  /* If any element of $arr is an array itself, the array_sum
   will be used. Alternatively, the values could be used by
   recursion. Returns the integer part (floor) */
 
function array_pitag_sum($arr) {
    if(
is_array($arr) {
     
$ret = 0;
      foreach(
$arr as $i) {
        if(
is_array($i)) {
         
$s = array_sum($i);
         
$ret += $s*$s;
        } else {
         
$ret += $i*$i;
        }
      }
      return
floor(sqrt($ret));
    } else {
      return
$arr;
    }
  }
?>
Tobias Schlemmer 28-Jul-2006 04:11
<?php
$array1
= array('1'=>'1','2'=>'2','3'=>'3');
$array2 = array(          '2'=>'1','3'=>'2','4'=>'3');
$array3 = array(                  '3'=>'1','4'=>'2','5'=>'3');
$array  = array_sum_values( $array1, $array2, $array3 );
print_r($array);

/**
 * Sums the values of the arrays be there keys (PHP 4, PHP 5)
 * array array_sum_values ( array array1 [, array array2 [, array ...]] )
 */
function array_sum_values() {
   
$return = array();
   
$intArgs = func_num_args();
   
$arrArgs = func_get_args();
    if(
$intArgs < 1) trigger_error('Warning: Wrong parameter count for array_sum_values()', E_USER_WARNING);
   
    foreach(
$arrArgs as $arrItem) {
        if(!
is_array($arrItem)) trigger_error('Warning: Wrong parameter values for array_sum_values()', E_USER_WARNING);
        foreach(
$arrItem as $k => $v) {
           
$return[$k] += $v;
        }
    }
    return
$return;
}
/* result:
Array
(
    [1] => 1
    [2] => 3
    [3] => 6
    [4] => 5
    [5] => 3
)
*/
?>
jodymickey at yahoo dot com 02-Jun-2006 12:53
In reference to KageKonjou's array_mode function...

If you only want to know the value in the array that occurs most (and not the number of times it actually occured), you can use this short function.  It also suffers from the same problem in that if there is more than one mode, it will return only one.
<?php
   
function array_mode($array)
    {
        if(!
is_array($array)) return false;
       
asort(array_count_values($array));
        return
array_pop($array);
    }
?>
Moslehi[atsign]Gmail[dot]com 18-Mar-2006 09:43
A simple example for numeric values :

<?PHP

function array_average($arr){
$sum = array_sum($arr);
$num = sizeof($arr);
echo
$sum/$num;
}

$myarray = array(1,2,3,4);
array_average($myarray); // displays 2.5 as average of 1,2,3,4

?>

[Arash Moslehi]
darianlassan at yahoo dot de 04-Nov-2005 10:27
function array_avg(&$array)
{
  //**
    returns the average value of all array-values
    or false if no values in array (or not an array)
  **//

  if (!is_array($array) || count($array)==0)
    return false;
  else
    return array_sum($array)/count($array);
} // array_avg()

Please add this function to PHP.
mroach at mroach dot com 28-Sep-2005 05:36
I ran into a situation where I only wanted to sum elements of an array for certain keys. For that, I wrote this function

<?

function array_sum_by_key()
{
   
$args = func_get_args();
   
   
$arr = array_shift($args);
           
   
$to_sum = is_array($args[0]) ? $args[0] : $args;
   
   
$sum = 0;

    foreach (
$arr as $k=>$v ) {
        if (
in_array($k, $to_sum) ) {
           
$sum += $v;
        }
    }
   
    return
$sum;
}

$arr = array (
   
'dog' => 1,
   
'cat' => 2,
   
'rat' => 4,
   
'mat' => 8,
   
'bat' => 16
);

echo
array_sum_by_key($arr, 'dog', 'mat');

// Result: 9

?>

Alternatively, you can pass the keys to sum as an array

<?

$to_sum
= array('dog', 'bat');

echo
array_sum_by_key($arr, $to_sum);

// Result: 17

?>
KageKonjou at GMail dot com 13-Aug-2005 01:52
Not sure where else to put this, but I added something that determines the most commonly occuring item in an array.  Known Bugs: It will always return the first value if no mode are found, and the first mode found if more are found of same or lesser count.

<?php
function array_mode($array) {
 
$count = array();
 foreach (
$array as $item) {
 
$count[$item]++;
 }
 
$mostcommon = "";
 
$iter = 0;
 foreach (
$count as $k => $v) {
  if (
$v > $iter) {
  
$mostcommon = $k;
  
$iter = $v;
  }
 }
 return array(
"mode" => $mostcommon, "count" => $count[$mostcommon]);
}
?>
punchto at hotmail dot com 16-Mar-2005 01:36
Microsoft Excel - SUMIF()

function sumif($array,$criteria,$sum_array){
  if(is_array($array) && is_array($sum_array) && trim($criteria)!= ""){
    $array_count = (count($array) < count($sum_array)) ? count($array):count($sum_array);
    for($i=0;$i<$array_count;$i++){
      if(ereg("^<",$criteria)){
        $value = ereg_replace("^<","",$criteria);
        $result += $array[$i] < $value ? $sum_array[$i]:0;
      }
      elseif(ereg("^>",$criteria)){
        $value = ereg_replace("^>","",$criteria);
        $result += $array[$i] > $value ? $sum_array[$i]:0;
      }
      else{
        $value = $criteria;
        $result += $array[$i] == $value ? $sum_array[$i]:0;
      }
     
    }
    return $result ? $result:0;
  }
}
adam at laural dot com dot au 02-Mar-2005 11:07
Here's a function to return the sum of a portion of an array:

function array_partial_sum($array, $start, $length){
    $new_array = array_slice($array, $start, $length);
    return array_sum($new_array);
}

$array = array(1, 2, 3, 4, 5);
print array_partial_sum($array, 0, 3);  // prints 6
ncheung at maine dot rr dot com 08-Feb-2005 12:32
For clarity, array indices containing boolean values such as TRUE and FALSE are added up as though they are 1 and 0 respectively.
mucello NOO SPAM @ weatherimages dOt org 23-Oct-2003 08:14
If you want to find the AVERAGE of the values in your array, use the sum and count functions together.  For example, let's say your array is $foo and you want the average...

<?php
$average_of_foo
= array_sum($foo) / count($foo);
?>
mcrm at NOTNEEDIT dot freemal dot it 14-Aug-2003 02:10
Hi people, if someone is searching a function that works also with multimension array, i suggest this :

<?php
function cw_array_count($a) {
  if(!
is_array($a)) return $a;
  foreach(
$a as $key=>$value)
    
$totale += cw_array_count($value);
  return
$totale;
}

$a[0][E][PS][P][a1]=1;
$a[0][E][PS][P][a2]=2;
$a[0][E][PJ][P][a2]=2;
$a[1][E][PS][E][a3]=3;

echo
cw_array_count($a[0]);
// or
echo cw_array_count($a[0][E]);
?>

Bye, Bye.
R.Martina
drverieevil at REMOVEMEasenne dot org 30-Jul-2003 07:44
If some array elements arent integers, function will change them to integers (content of array will not change) type and then sum them.

Example:
<?php
$foo
[] = "12";
$foo[] = 10;
$foo[] = "bar";
$foo[] = "summer";
echo
array_sum ($foo); //same as echo "22";
?>

 
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