Recursive Functions are functions that auto-call themself. Generally, a recursive function returns a value that are passed as argument, so the value is passed from an auto-call to the other, until it is returned.
Recursive functions are very useful in equations with factorial numbers and some operatios with multi-dimensional array.
Factorials are written like 6! and this means: 6 * 5 * 4 * 3 * 2 * 1. So 6! is 4320 and 4! is 24.
In the fallowing example we have a recursive function that finds the factorial of a number "$nr" (here 8).

<?php
// this function auto-calls itself (decrementing $nr) until $nr is 0
function factorial($nr) {
  if($nr > 0) $re = $nr * factorial($nr-1);
  else if($nr == 0) $re = 1;

  return $re;
}

echo '8 factorial is: '. factorial(8);        // 8 factorial is: 45360
?>

- To see another example, visit this page: Get all the unique numbers from two-dimensional array.

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which tag adds an image in web page?
<div> <img> <span>
<img src="http://coursesweb.net/imgs/webcourses.gif" width="191" height="63" alt="Courses-Web" />
Which of these CSS codes displays the text oblique?
font-style: italic; text-decoration: underline; font-weight: 500;
#id {
  font-style: italic;
}
Click on the jQuery function used to hide with animation a HTML element.
click() hide() show()
$(document).ready(function() {
  $(".a_class").click(function(){ $(this).hide("slow"); });
});
Click on the correctly defined function in PHP.
fname function() {} function fname() {} function $fname() {};
function fname($a, $b) {
  echo $a * $b;
}
Recursive Functions in PHP

Last accessed pages

  1. Qwop (3650)
  2. AJAX and XML (1109)
  3. Butterfly Kyodai (6814)
  4. Zuma Deluxe (10133)
  5. Zodiac Signs JavaScript code (2798)

Top accessed pages

  1. Courses Web: PHP-MySQL JavaScript Ajax HTML CSS Flash-AS3 (47842)
  2. Read Excel file data in PHP - PhpExcelReader (35965)
  3. PHP-MySQL free course, online tutorials PHP MySQL code (35572)
  4. Get Attribute (ID, Class, Name, Title, Src) with jQuery (32081)
  5. PHP PDO - exec (INSERT, UPDATE, DELETE) MySQL (29348)