array_sum

(PHP 4 >= 4.0.4, PHP 5)

array_sumCalculate the sum of values in an array

Description

number array_sum ( array $array )

array_sum() returns the sum of values in an array.

Parameters

array

The input array.

Return Values

Returns the sum of values as an integer or float.

Changelog

Version Description
4.2.1 PHP versions prior to 4.2.1 modified the passed array itself and converted strings to numbers (which most of the time converted them to zero, depending on their value).

Examples

Example #1 array_sum() examples

<?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";
?>

The above example will output:

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

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User Contributed Notes 7 notes

up
4
mucello NOO SPAM @ weatherimages dOt org
11 years ago
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);
?>
up
3
drverieevil at REMOVEMEasenne dot org
11 years ago
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";
?>
up
3
punchto at hotmail dot com
9 years ago
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;
  }
}
up
1
ncheung at maine dot rr dot com
9 years ago
For clarity, array indices containing boolean values such as TRUE and FALSE are added up as though they are 1 and 0 respectively.
up
0
didatus at dynarize dot de
1 month ago
If you want to check if there are for example only strings in an array, you can use a combination of array_sum and array_map like this:

<?php

function only_strings_in_array($arr) {
    return
array_sum(array_map('is_string', $arr)) == count($arr);
}

$arr1 = array('one', 'two', 'three');
$arr2 = array('foo', 'bar', array());
$arr3 = array('foo', array(), 'bar');
$arr4 = array(array(), 'foo', 'bar');

var_dump(
   
only_strings_in_array($arr1),
   
only_strings_in_array($arr2),
   
only_strings_in_array($arr3),
   
only_strings_in_array($arr4)
);
?>

This will give you the following result:
bool(true)
bool(false)
bool(false)
bool(false)
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-1
herenvardo at gmail dot com
7 years ago
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;
    }
  }
?>
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-6
hdeus at yahoo dot com
6 years ago
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);
   
   
}

?>
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