... PHP 4 >= 4.0.4) array_sum -- Calculate the sum of values in an array. mixed array_sum ( array array) . array_sum() returns the sum of values in an array as an integer or float. ... a = array(2, 4, 6, 8); 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"; . ... Note: PHP versions prior to 4.0.6 modified the passed array itself and converted strings to numbers (which most of the time converted them to zero, depending on their value). ...