w3resource

PHP Array Exercises : Sort an associative array

PHP Array: Exercise-8 with Solution

Write a PHP script to sort the following associative array :

array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40") in
a) ascending order sort by value
b) ascending order sort by Key
c) descending order sorting by Value
d) descending order sorting by Key

Sample Solution:

PHP Code:

<?php
echo "
Associative array : Ascending order sort by value
";
$array2=array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40"); asort($array2);
foreach($array2 as $y=>$y_value)
{
echo "Age of ".$y." is : ".$y_value."
";
}
echo "
Associative array : Ascending order sort by Key
";
$array3=array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40"); ksort($array3);
foreach($array3 as $y=>$y_value)
{
echo "Age of ".$y." is : ".$y_value."
";
}
echo "
Associative array : Descending order sorting by Value
";
$age=array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40");
arsort($age);
foreach($age as $y=>$y_value)
{
echo "Age of ".$y." is : ".$y_value."
";
}
echo "
Associative array : Descending order sorting by Key
";
$array4=array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40"); krsort($array4);
foreach($array4 as $y=>$y_value)
{
echo "Age of ".$y." is : ".$y_value."
";
} 
?>

Sample Output:

Associative array : Ascending order sort by value           
Age of Sophia is : 31                                       
Age of William is : 39                                      
Age of Ramesh is : 40                                       
Age of Jacob is : 41                                        
                                                            
Associative array : Ascending order sort by Key             
Age of Jacob is : 41                                        
Age of Ramesh is : 40                                       
Age of Sophia is : 31                                       
Age of William is : 39                                      
                                                            
Associative array : Descending order sorting by Value       
Age of Jacob is : 41                                        
Age of Ramesh is : 40                                       
Age of William is : 39                                      
Age of Sophia is : 31                                       
                                                            
Associative array : Descending order sorting by Key         
Age of William is : 39                                      
Age of Sophia is : 31                                       
Age of Ramesh is : 40  
Age of Jacob is : 41 

Flowchart:

Flowchart: Sort an  associative array

PHP Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a PHP script that inserts a new item in an array in any position.
Next: Write a PHP script to calculate and display average temperature, five lowest and highest temperatures.

What is the difficulty level of this exercise?



PHP: Tips of the Day

Convert a PHP object to an associative array

Just typecast it

$array = (array) $yourObject;

From Arrays:

If an object is converted to an array, the result is an array whose elements are the object's properties. The keys are the member variable names, with a few notable exceptions: integer properties are unaccessible; private variables have the class name prepended to the variable name; protected variables have a '*' prepended to the variable name.These prepended values have null bytes on either side.

Example: Simple Object

$object = new StdClass;
$object->foo = 1;
$object->bar = 2;

var_dump( (array) $object );

Output:

array(2) {
  'foo' => int(1)
  'bar' => int(2)
}

Example: Complex Object

class Foo
{
    private $foo;
    protected $bar;
    public $baz;

    public function __construct()
    {
        $this->foo = 1;
        $this->bar = 2;
        $this->baz = new StdClass;
    }
}

var_dump( (array) new Foo );

Output (with \0s edited in for clarity):

array(3) {
  '\0Foo\0foo' => int(1)
  '\0*\0bar' => int(2)
  'baz' => class stdClass#2 (0) {}
}

Output with var_export instead of var_dump:

array (
  '' . "\0" . 'Foo' . "\0" . 'foo' => 1,
  '' . "\0" . '*' . "\0" . 'bar' => 2,
  'baz' =>
  stdClass::__set_state(array(
  )),
)

Typecasting this way will not do deep casting of the object graph and you need to apply the null bytes (as explained in the manual quote) to access any non-public attributes. So this works best when casting StdClass objects or objects with only public properties. For quick and dirty (what you asked for) it's fine.

Also see this in-depth blog post:

  • Fast PHP Object to Array conversion

Ref : https://bit.ly/3fqiV2E