Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

PHP Challenges: Compute and return the square root of a given number

PHP Challenges - 1: Exercise-8 with Solution

Write a PHP program to compute and return the square root of a given number.

Input : 16

Explanation :

PHP: Compute and return the square root of a given number

Sample Solution :

PHP Code :

<?php
function my_sqrt($n)
{
  $x = $n;
  $y = 1;
  while($x > $y)
  {
    $x = ($x + $y)/2;
    $y = $n/$x;
  }
  return $x;
}
print_r(my_sqrt(16)."\n");
print_r(my_sqrt(14)."\n");
?>

Sample Output: 

4                                                           
3.7416573867739

Flowchart:

PHP Flowchart: Compute and return the square root of a given number

PHP Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a PHP program to find three numbers from an array such that the sum of three consecutive numbers equal to a given number.
Next: Write a PHP program to find a single number in an array that doesn't occur twice.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



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