Quicksort Algorithm – Difference Between PHP and JavaScript
Quicksort Algorithm – Difference Between PHP and JavaScript
Join the DZone community and get the full member experience.
Join For FreeJumpstart your Angular applications with Indigo.Design, a unified platform for visual design, UX prototyping, code generation, and app development.
Here’s some Friday fun. Let me show you one sorting algorithm, perhaps the most known of all them – the quick sort, implemented both on PHP and JavaScript. Although the code look similar between both languages, there are few differences, that show the importance of the syntax knowledge!
PHP
<?php
$unsorted = array(2,4,5,63,4,5,63,2,4,43);
function quicksort($array)
{
if (count($array) == 0)
return array();
$pivot = $array[0];
$left = $right = array();
for ($i = 1; $i < count($array); $i++) {
if ($array[$i] < $pivot)
$left[] = $array[$i];
else
$right[] = $array[$i];
}
return array_merge(quicksort($left), array($pivot), quicksort($right));
}
$sorted = quicksort($unsorted);
print_r($sorted);
JavaScript
var a = [2,4,5,63,4,5,63,2,4,43];
function quicksort(arr)
{
if (arr.length == 0)
return [];
var left = new Array();
var right = new Array();
var pivot = arr[0];
for (var i = 1; i < arr.length; i++) {
if (arr[i] < pivot) {
left.push(arr[i]);
} else {
right.push(arr[i]);
}
}
return quicksort(left).concat(pivot, quicksort(right));
}
console.log(quicksort(a));
Note that the first conditional statement is quite important! While in PHP the count function will return 0 either on a NULL value or an empty array and you can substitute it with something like count($array) < 2
if (count($array) < 2)
return $array;
in JavaScript you cannot use that because of the presence of the ‘undefined’ value when an “empty” array is passed as an argument. Thus you’ve the conditional above:
// this will result with an error
if (arr.length < 2)
return arr;
Coming Up Next …
An iterative version of the algorithm next Friday!
Take a look at an Indigo.Design sample application to learn more about how apps are created with design to code software.
Published at DZone with permission of Stoimen Popov , DZone MVB. See the original article here.
Opinions expressed by DZone contributors are their own.
{{ parent.title || parent.header.title}}
{{ parent.tldr }}
{{ parent.linkDescription }}
{{ parent.urlSource.name }}