Array sorting by key value in php [duplicate] - php

Question

This question already has answers here:
How to Sort a Multi-dimensional Array by Value
(16 answers)
Closed 2 years ago.
I would like to sort below array based on amount but I don't know how. Anyone help me
Array(
[0] => Array
(
[id] => 1
[amount] => 20
)
[1] => Array
(
[id] => 2
[amount] => 30
)
[2] => Array
(
[id] => 3
[amount] => 10
)
)

Answer 1

Something like
PHP7+
usort($array, function($a, $b){
return $a['amount'] <=> $b['amount'];
});
What is <=> (the 'Spaceship' Operator) in PHP 7?
< PHP 7
usort($array, function($a, $b){
if( $a['amount'] == $b['amount'] )
return 0;
else if($a['amount'] > $b['amount'])
return 1;
else
return -1
});
OR you can just subtract them like everyone else...

Answer 2

usort [1] will do the job using a custom comparator function which indexes into the amount property and performs a standard integer comparison for less than/greater than. Sort descending with $b["amount"] - $a["amount"] if you wish.
$data = [
[
"id" => 1,
"amount" => 20
],
[
"id" => 2,
"amount" => 30,
],
[
"id" => 3,
"amount" => 10
]
];
usort($data, function ($a, $b) {
return $a["amount"] - $b["amount"];
});
print_r($data);
Output:
Array
(
[0] => Array
(
[id] => 3
[amount] => 10
)
[1] => Array
(
[id] => 1
[amount] => 20
)
[2] => Array
(
[id] => 2
[amount] => 30
)
)

Answer 3

Use usort.
E.g
function sortByAmount($x, $y) {
return $x['amount'] - $y['amount'];
}
usort($array, 'sortByAmount');
echo "<pre>"; print_r($array);

Answer 4

Use usort function like this (know more about usort click here):
$array = array(array('id'=>1,'amount'=>20),array('id'=>2,'amount'=>30),array('id'=>3,'amount'=>10));
Create custom function like this:
function sortByAmount($x,$y){
return $x['amount']-$y['amount'];
}
Then use usort function like this:
usort($array,'sortByAmount');
// then print
echo"<pre>"; print_r($array);