PHP Data Types : Objects

Last update on May 28 2022 12:32:01 (UTC/GMT +8 hours)

Description

An object is a data type which stores not only data but also information on how to process that data. Unlike the other data types in PHP, an object must be explicitly declared.

At first, we must declare a class of object. A class is a structure which contains properties and methods.

Classes are defined with the class keyword. We define the data type in the object class, and then we use the data type in instances of that class.

Example:

<?php class student
{
function marks_calculation()
{         
echo "Display marks";
}
}
$student1 = new student;
$student1->marks_calculation(); 
?>

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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