PHP Exercises: Check if two numbers are approximately equal to each other

Last update on May 30 2022 11:42:19 (UTC/GMT +8 hours)

PHP: Exercise-94 with Solution

Write a PHP program to check if two numbers are approximately equal to each other.

Note: Use abs() to compare the absolute difference of the two values to epsilon. Omit the third parameter, epsilon, to use a default value of 0.001.

Sample Solution: -

PHP Code:

<?php
//Licence: https://bit.ly/2CFA5XY
function approximatelyEqual($number1, $number2, $epsilon = 0.001)
{
    if (abs($number1 - $number2) < $epsilon)
     return 1;
    else
     return 0;
}
print_r(approximatelyEqual(10.0, 10.00001));  
echo("\n");
print_r(approximatelyEqual(10.0, 10.01));

?>

Sample Output:

1
0

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to sort a collection of given arrays or objects by key.
Next: Write a PHP program to check if a given string starts with a given substring.

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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