I have 2 arrays as below:
array(2) { ["2018-05"]=> string(2) "15" ["2018-06"]=> string(3) "100" }
array(1) { ["2018-05"]=> string(1) "5" }
I wish to do calculation to find the difference so it will return:
array(2) { ["2018-05"]=> string(2) "10" ["2018-06"]=> string(3) "100" }
As this is a multidimensional array, I'm not sure how to show the "year-month" as the array key, can someone please enlighten me?
Thanks.
Try this code
$a = ["2018-05"=> "15", "2018-06"=> "100" ];
$b = ["2018-05"=> "5"];
$c = $a;
foreach($b as $k=> $i){
if(array_key_exists($k,$c)){
$c[$k] = $a[$k] - $b[$k];
}
else{
$c[$k] = 0-$i;
}
}
Assuming that you don't want to take into account same values and you want absolute values, this should work
$els[]["2018-05"]="15";
$els[]["2018-06"]="100";
$els[]["2018-05"]="5" ;
$els[]["2018-05"]="1" ;//added
$els[]["2018-06"]="50";//added
$newEls = [];
foreach($els as $key => $el){
$newEls[key($el)] = $el[key($el)];
foreach($els as $key2 => $el2){
if(key($els[$key]) == key($els[$key2]) && $els[$key][key($els[$key])] != $els[$key2][key($els[$key2])]){
$newEls[key($el)] = abs($els[$key][key($els[$key])] - $els[$key2][key($els[$key2])]);
}
}
}
echo "<pre>";print_r($newEls);
If you want to keep same values like [0]["2018-05"]="15" and [1]["2018-05"]="15" it's necessary another approach. Because maybe the best approach is to use queues.
<?php
$a = ['2018-05'=> '15', '2018-06'=> '100'];
$b = ['2018-05'=> '5'];
$years = array_map(NULL, $a, $b);
$years = array_combine(array_keys($a), $years);
$differences = array_map(function ($year_diffs) : float {
// Did we get a pair to compare?
$has_diff = isset($year_diffs[0]) and isset($year_diffs[1]);
// If we got a pair then compare, else assume we got one.
$diff = $has_diff ? abs($year_diffs[0] - $year_diffs[1]) : $year_diffs[0];
return $diff;
}, $years);
var_dump($differences);
I've had to assume a few things
I feel like whatever your real system is, probably violates the above criteria but you'd need to provide more context for a different solution
