Given these two arrays:
$first=array(
'books'=>1,
'videos'=>5,
'tapes'=>7,
);
$second=array(
'books'=>3,
'videos'=>2,
'radios'=>4,
'rc cars'=>3,
);
I would like to combine them so that I end up with
$third=array(
'books'=>4,
'videos'=>7,
'tapes'=>7,
'radios'=>4,
'rc cars'=>3,
);
I saw a function here: How to sum values of the array of the same key? but it looses the Key.
You can use something along the lines of:
function sum_associatve($arrays){
$sum = array();
foreach ($arrays as $array) {
foreach ($array as $key => $value) {
if (isset($sum[$key])) {
$sum[$key] += $value;
} else {
$sum[$key] = $value;
}
}
}
return $sum;
}
$third=sum_associatve(array($first,$second));
array_merge() does not sum the values. For duplicate keys, it uses the value from the second array.Just to be different... Uses func_get_args(), closures and enforces arguments to be arrays:
function sum_associative()
{
$data = array();
array_walk($args = func_get_args(), function (array $arg) use (&$data) {
array_walk($arg, function ($value, $key) use (&$data) {
if (isset($data[$key])) {
$data[$key] += $value;
} else {
$data[$key] = $value;
}
});
});
return $data;
}
