PHP Array Exercises : Returns values of the first array that are not in the second array

Last update on May 30 2022 11:50:12 (UTC/GMT +8 hours)

PHP Array: Exercise-45 with Solution

Write a PHP script to do a multi-dimensional difference, i.e. returns values of the first array that are not in the second array.

Sample Solution:

PHP Code:

<?php
$color1 = array( array('Red', 80), array('Green', 70), array('white', 60) ); 
        
$color2 = array( array('Green', 70), array('Black', 95) ); 
        
$color = array_udiff($color1, $color2, create_function( 
    '$a,$b', 'return strcmp( implode("", $a), implode("", $b) ); ') 
    ); 
        
print_r($color);
?>

Sample Output:

Array                                                       
(                                                           
    [0] => Array                                            
        (                                                   
            [0] => Red                                      
            [1] => 80                                       
        )                                                   
                                                            
    [2] => Array                                            
        (                                                   
            [0] => white                                    
            [1] => 60                                       
        )                                                   
                                                            
)

Flowchart:

PHP Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a PHP a function to remove a specified duplicate entry from an array.
Next: Write a PHP function to check whether all array values are strings or not.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

PHP: Tips of the Day

How to Sort Multi-dimensional Array by Value?

Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

Example:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual

Ref : https://bit.ly/3i77vCC