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PHP Array Exercises : Find unique values from multidimensional array and flatten them in zero depth

PHP Array: Exercise-42 with Solution

Write a PHP function to find unique values from multidimensional arrays and flatten them in 0 depth.

Sample Solution:

PHP Code:

<?php
function array_flat($my_array) 
    { 
         $fa = array();
		 $l = 0;
        foreach($my_array as $k => $v ) 
        { 
            if( !is_array( $v ) ) 
            { 
               $fa[ ]= $v; 
                
                continue;           
            } 
             $l++; 
            $fa= array_flat( $v, $fa, $l ); 
            $l--; 
      } 
       
        if( $l == 0 ) $fa = array_values( array_unique( $fa ) );         
        return $fa;       
    } 
$tmp = array( 'a' => array( -1,-2, 0, 2, 3 ), 'b' => array( 'c' => array( -1, 0, 2, 0, 3 ) ) ); 
print_r(array_flat($tmp));
?>

Sample Output:

Array                                                       
(                                                           
    [0] => -1                                               
    [1] => 0                                                
    [2] => 2                                                
    [3] => 3                                                
) 

Flowchart:

Flowchart: PHP - Find unique values from multidimensional array and flatten them in zero depth

PHP Code Editor:

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Previous: Write a PHP program to identify the email addresses which are not unique.
Next: Write a PHP script to merge two commas separated lists with unique value only.

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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