php array sort by key value

1$inventory = array(
2
3   array("type"=>"fruit", "price"=>3.50),
4   array("type"=>"milk", "price"=>2.90),
5   array("type"=>"pork", "price"=>5.43),
6
7);
8$price = array_column($inventory, 'price');
9array_multisort($price, SORT_DESC, $inventory);

1  $weight = [
2    'Pete' => 75, 
3    'Benjamin' => 89,
4    'Jonathan' => 101
5  ];  	
6  ksort($weight);

1$weight = [
2    'Pete' => 75,
3    'Benjamin' => 309,
4    'Jonathan' => 101
5];
6asort($weight);
7/*
8weight is now:
9Array
10(
11    [Pete] => 75
12    [Jonathan] => 101
13    [Benjamin] => 309
14)
15To sort descending instead use: arsort
16*/

1
2usort($array, function ($a, $b) {
3  return ($a['specific_key'] < $b['specific_key']) ? -1 : 1;
4});
5

1$inventory = [
2	['price' => 10.99, 'product' => 'foo 1'],
3    ['price' => 5.99, 'product' => 'foo 2'],
4  	['price' => 100, 'product' => 'foo 3'],
5  
6];
7
8$price = array_column($inventory, 'price');
9
10array_multisort($price, SORT_DESC, $inventory);

1To PHP sort array by key, you should use: 
2	ksort() (for ascending order) or krsort() (for descending order). 
3      
4To PHP sort array by value, you will need functions:
5	asort() and arsort() (for ascending and descending orders).