PHP Date Exercises : Add/subtract the number of days from a particular date

Last update on May 30 2022 11:45:49 (UTC/GMT +8 hours)

PHP date: Exercise-16 with Solution

Write a PHP script to add/subtract the number of days from a particular date.

Sample Solution:

PHP Code:

<?php
$dt='2011-01-01';
echo 'Original date : '.$dt."\n";
$no_days = 40;
$bdate = strtotime("-".$no_days." days", strtotime($dt));
$adate = strtotime("+".$no_days." days", strtotime($dt));
echo 'Before 40 days : '.date("Y-m-d", $bdate)."\n";
echo 'After  40 days : '.date("Y-m-d", $adate)."\n";
?>

Sample Output:

Original date : 2011-01-01                                  
Before 40 days : 2010-11-22                                 
After  40 days : 2011-02-10

Flowchart :

PHP Code Editor:

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Previous: Write a PHP script to check if a date is a weekend or not.
Next: Write a PHP function to get start and end date of a week (by week number) of a particular year.

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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