PHP Array Exercises : Convert a string to an array

Last update on May 30 2022 11:48:14 (UTC/GMT +8 hours)

PHP Array: Exercise-55 with Solution

Write a PHP function to convert a string to an array (trimming every line and remove empty lines).

Sample Solution:

PHP Code:

<?php
 $string = "  IANA is the global coordinator of the DNS root. 
The root is the upper-most part of the DNS hierarchy, 
and involves delegating administrative responsibility 
of “top-level domains”, which are the last segment of 

a domain name, such as .com, .uk and .nz. Part of this 
task includes evaluating requests to change the operators 

of country code domains, as well as day-to-day maintenance
of the details of the existing operators. ";
$result = array_filter(array_map('trim', explode("\n", $string)), 'strlen');
print_r($result);
?>

Sample Output:

Array                                                       
(                                                           
    [0] => IANA is the global coordinator of the DNS root.  
    [1] => The root is the upper-most part of the DNS hierar
chy,                                                        
    [2] => and involves delegating administrative responsibi
lity                                                        
    [3] => of “top-level domains”, which are the last segmen
t of                                                        
    [5] => a domain name, such as .com, .uk and .nz. Part of
 this                                                       
    [6] => task includes evaluating requests to change the o
perators                                                    
    [8] => of country code domains, as well as day-to-day ma
intenance                                                   
    [9] => of the details of the existing operators.        
)

Flowchart:

PHP Code Editor:

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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