How can I sum all key values and then remove duplicate keys ?
My example array:
$eg=array("105"=>"3", "106"=>"1", "122"=>"7", "105"=>"1", "310"=>"3", "105"=>"5", "310"=>"2");
I want to output an array that will have sumed the values and removed duplicate keys:
[105]=9
[106]=1
[122]=7
[310]=5
("105"=>"9", "106"=>"1", "122"=>"7", "310"=>"5");
Thank you very much,
B.
Array keys have to be unique, so I don't think your plan will work. Try print_r($eg) to see that your duplicate keys are not even being stored like you think they are.
If there is a way to store an array with duplicate keys (and that's a BIG if), here is how you could do what you're wanting to do...
sort($eg);
$new = array();
foreach ($eg as $k => $v) {
if (array_key_exists($k, $new)) {
$new[$k] += $v;
} else {
$new[$k] = $v;
}
}
There are probably faster or more elegant solutions, but I haven't had my coffee yet. 
And I don't think your plan will work anyway. Could you do this with multiple input arrays to get around the duplicate key restriction?
I did not know an array is allowed to have duplicate keys?
In my mind
$eg["105"] is always $eg["105"]
How do you get duplicate keys?
With different values?
But maybe it is possible.
In your way to assign perhaps. But at least This wont work:
<?php
$eg["105"] = "3";
$eg["105"] = "1";
$eg["105"] = "5";
print_r($eg);
?>About this I do not know
<?php
$eg[105] = "3"; // key is integer
$eg["105"] = "5"; // key is string
print_r($eg);
?>