Sort array by mutiple fields (closest to number) - php

Question

How can I sort a array by two(one) different values?
So I have a array like this:
array(
array(
'id' => 10,
'total' => 38,
'entry' => 400
),
array(
'id' => 4,
'total' => 34,
'entry' => 3100
),
array(
'id' => 2,
'total' => 34,
'entry' => 3150
),
array(
'id' => 8,
'total' => 34,
'entry' => 2980
),
);
The array is already sorted by the key total, but they all have the same value in total. So I need to sort by who is closest to 3000 by entry.
Edit
The array should be first sorted by total and then entry, since entry is only there so I can differentiate who is the best.
So the array should look like this:
array(
array(
'id' => 10,
'total' => 38,
'entry' => 400
),
array(
'id' => 8,
'total' => 34,
'entry' => 2980
),
array(
'id' => 4,
'total' => 34,
'entry' => 3100
),
array(
'id' => 2,
'total' => 34,
'entry' => 3150
)
);

Answer 1

Try this:
usort($arr, function ($a, $b) {
if ($a['total'] == $b['total']) { // Only compare on entry when the totals are the same.
return abs($a['entry'] - 3000) > abs($b['entry'] - 3000);
}
return $a['total'] < $b['total'];
});
print_r($arr);
Output:
Array
(
[0] => Array
(
[id] => 2
[total] => 35
[entry] => 3150
)
[1] => Array
(
[id] => 8
[total] => 34
[entry] => 2980
)
[2] => Array
(
[id] => 4
[total] => 34
[entry] => 3100
)
[3] => Array
(
[id] => 6
[total] => 34
[entry] => 3250
)
[4] => Array
(
[id] => 3
[total] => 32
[entry] => 3400
)
)
Here's how it works: it compares the totals, but if they're the same, it compares the absolute value of the difference between entry and 3000 of both entrys.
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