PHP Regular expression - Exercises, Practice, Solution

Last update on May 30 2022 11:45:38 (UTC/GMT +8 hours)

PHP regular expression [ 7 exercises with solution]

1. Write a PHP script that checks if a string contains another string. Go to the editor
Click me to see the solution

2. Write a PHP script that removes the last word from a string. Go to the editor
Sample string : 'The quick brown fox'
Expected Output : The quick brown
Click me to see the solution

3. Write a PHP script that removes the whitespaces from a string. Go to the editor
Sample string : 'The quick " " brown fox'
Expected Output : Thequick""brownfox
Click me to see the solution

4. Write a PHP script to remove nonnumeric characters except comma and dot. Go to the editor
Sample string : '$123,34.00A'
Expected Output : 12,334.00
Click me to see the solution

5. Write a PHP script to remove new lines (characters) from a string. Go to the editor
Sample strings : "Twinkle, twinkle, little star,\nHow I wonder what you are.\nUp above the world so high,\nLike a diamond in the sky.";
Expected Output : "Twinkle, twinkle, little star, How I wonder what you are. Up above the world so high, Like a diamond in the sky."
Click me to see the solution

6. Write a PHP script to extract text (within parenthesis) from a string. Go to the editor
Sample strings : 'The quick brown [fox].'
Expected Output : 'fox'
Click me to see the solution

7. Write a PHP script to remove all characters from a string except a-z A-Z 0-9 or " ". Go to the editor
Sample string : abcde$ddfd @abcd )der]
Expected Result : abcdeddfd abcd der
Click me to see the solution

PHP Code Editor:

More to Come !

Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.

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