Bash

#!/bin/bash

# Fibonacci numbers
# Writes an infinite series to stdout, one entry per line
function fib() {
  local a=1
  local b=1
  while true ; do
    echo $a
    local tmp=$a
    a=$(( $a + $b ))
    b=$tmp
  done
}

# output the 10th element of the series and halt
fib | head -10 | tail -1

C

#include <stdio.h>

/* the n-th fibonacci number.
 */
unsigned int fib(unsigned int n) {
  unsigned int a = 1, b = 1;
  unsigned int tmp;
  while (--n >= 0) {
    tmp = a;
    a += b;
    b = tmp;
  }
  return a;
}

main() {
  printf("%u", fib(10));
}

C++

#include <iostream>

using namespace std;

//! fibonacci numbers with gratuitous use of templates.
//! \param n an index into the fibonacci series
//! \param fib0 element 0 of the series
//! \return the nth element of the fibonacci series
template <class T>
T fib(unsigned int n, const T& fib0) {
  T a(fib0), b(fib0);
  while (--n >= 0) {
    T tmp(a);
    a += b;
    b = tmp;
  }
  return a;
}

int main(int argc, char **argv) {
  cout << fib(10, 1U);
}

Java

package foo;

import java.util.Iterator;

/**
 * the fibonacci series implemented as an Iterable.
 */
public final class Fibonacci implements Iterable<Integer> {
  /** the next and previous members of the series. */
  private int a = 1, b = 1;

  public Iterator<Integer> iterator() {
    return new Iterator<Integer>() {
      /** the series is infinite. */
      public boolean hasNext() { return true; }
      public Integer next() {
        int tmp = a;
        a += b;
        b = tmp;
        return a;
      }
      public void remove() { throw new UnsupportedOperationException(); }
    };
  }

  /**
   * the n<sup>th</sup> element of the given series.
   * @throws NoSuchElementException if there are less than n elements in the
   *   given Iterable's {@link Iterable#iterator iterator}.
   */
  public static <T>
  T nth(int n, Iterable<T> iterable) {
    Iterator<? extends T> it = iterable.iterator();
    while (--n > 0) {
      it.next();
    }
    return it.next();
  }

  public static void main(String[] args) {
    System.out.print(nth(10, new Fibonacci()));
  }
}

Javascript

/**
 * nth element in the fibonacci series.
 * @param n >= 0
 * @return the nth element, >= 0.
 */
function fib(n) {
  var a = 1, b = 1;
  var tmp;
  while (--n >= 0) {
    tmp = a;
    a += b;
    b = tmp;
  }
  return a;
}

document.write(fib(10));

Issue 12 - Javascript Regular Expressions

/foo/;  // a slash starting a line treated as a regexp beginning
"foo".match(/fo+$/);
// this line comment not treated as a regular expressions
"foo /bar/".test(/"baz"/);  // test string and regexp boundaries
var division = /\b\d+\/\d+/g;  // test char sets and escaping of specials
var allSpecials = /([^\(\)\[\]\{\}\-\?\+\*\.\^\$\/]+)\\/;

// test that slash used in numeric context treated as an operator
1 / 2;
1. / x;
x / y;
(x) / y;
1 /* foo */ / 2;
1 /* foo *// 2;
1/2;
1./x;
x/y;
(x)/y;

// test split over two lines.  line comment should not fool it
1//
/2;

x++/y;
x--/y;
x[y] / z;
f() / n;

// test that slash after non postfix operator is start of regexp
log('matches = ' + /foo/.test(foo));

// test keyword preceders
return /a regexp/;
division = notreturn / not_a_regexp / 2;  // keyword suffix does not match

// & not used as prefix operator in javascript but this should still work
&/foo/;

Perl

#!/usr/bin/perl

use strict;
use integer;

# the nth element of the fibonacci series
# param n - an int >= 0
# return an int >= 0
sub fib($) {
  my $n = shift, $a = 1, $b = 1;
  ($a, $b) = ($a + $b, $a) until (--$n < 0);
  return $a;
}

print fib(10);

Python

#!/usr/bin/python2.4

def fib():
  '''
  a generator that produces the elements of the fibonacci series
  '''

  a = 1
  b = 1
  while True:
    a, b = a + b, a
    yield a

def nth(series, n):
  '''
  returns the nth element of a series,
  consuming the earlier elements of the series
  '''

  for x in series:
    n = n - 1
    if n <= 0: return x

print nth(fib(), 10)

XML

<!DOCTYPE series PUBLIC "fibonacci numbers">

<series base="1" step="s(n-2) + s(n-1)">
  <element i="0">1</element>
  <element i="1">1</element>
  <element i="2">2</element>
  <element i="3">3</element>
  <element i="4">5</element>
  <element i="5">8</element>
  ...
</series>

HTML

<html>
  <head>
    <title>Fibonacci number</title>
  </head>
  <body>
    <noscript>
      <dl>
        <dt>Fibonacci numbers</dt>
        <dd>1</dd>
        <dd>1</dd>
        <dd>2</dd>
        <dd>3</dd>
        <dd>5</dd>
        <dd>8</dd>
        &hellip;
      </dl>
    </noscript>

    <script type="text/javascript"><!--
function fib(n) {
  var a = 1, b = 1;
  var tmp;
  while (--n >= 0) {
    tmp = a;
    a += b;
    b = tmp;
  }
  return a;
}

document.writeln(fib(10));
// -->
    </script>
  </body>
</html>

HTML using XMP

XHTML

<xhtml>
  <head>
    <title>Fibonacci number</title>
  </head>
  <body>
    <script type="text/javascript"><![CDATA[
function fib(n) {
  var a = 1, b = 1;
  var tmp;
  while (--n >= 0) {
    tmp = a;
    a += b;
    b = tmp;
  }
  return a;
}

document.writeln(fib(10));
]]>
    </script>
  </body>
</xhtml>

PHP

<html>
  <head>
    <title><?= 'Fibonacci numbers' ?></title>

    <?php
      // PHP has a plethora of comment types
      /* What is a
         "plethora"? */
      function fib($n) {
        # I don't know.
        $a = 1;
        $b = 1;
        while (--$n >= 0) {
          echo "$a\n";
          $tmp = $a;
          $a += $b;
          $b = $tmp;
        }
      }
    ?>
  </head>
  <body>
    <?= fib(10) ?>
  </body>
</html>

XSL (Issue 19)

<!-- Test elements and attributes with namespaces -->

<xsl:stylesheet xml:lang="en">
  <xsl:template match=".">
    <xsl:text>Hello World</xsl:text>
  </xsl:template>
</xsl:stylesheet>

Whitespace

Misc

// ends with line comment token
//

User submitted testcase for Bug 4

Javascript Snippets wrapped in HTML SCRIPT tags hides/destroys inner content

<script type="text/javascript">
   var savedTarget=null;                           // The target layer (effectively vidPane)
   var orgCursor=null;                             // The original mouse style so we can restore it
   var dragOK=false;                               // True if we're allowed to move the element under mouse
   var dragXoffset=0;                              // How much we've moved the element on the horozontal
   var dragYoffset=0;                              // How much we've moved the element on the verticle
   vidPaneID = document.getElementById('vidPane'); // Our movable layer
   vidPaneID.style.top='75px';                     // Starting location horozontal
   vidPaneID.style.left='75px';                    // Starting location verticle
<script>

The fact that the script tag was not closed properly was causing PR_splitSourceNodes to end without emitting the script contents.

Bug 8 - tabs mangled

If tabs are used to indent code inside <pre> IE6 and 7 won't honor them after the script runs. Code indented with tabs will be shown aligned to the left margin instead of the proper indenting shown in Firefox. I'm using Revision 20 of prettify.js, IE 6.0.29.00 in English and IE 7.0.5730.11 in Spanish.

one	Two	three	Four	five	|
Six	seven	Eight	nine	Ten	|
eleven	Twelve	thirteen	Fourteen	fifteen	|

Bug 14a - does not recognize <br> as newline

//comment
int main(int argc, char **argv)
{}

Bug 14b - comments not ignored

<!-- There's an HTML comment in my comment -->
<p>And another one inside the end tag</p>

Bug 20 - missing blank lines

<html>

<head>

Bug 21 - code doesn't copy and paste well in IE

<html>
  <head>
    <title>Test</title>
  </head>
</html>

To test this bug, disable overriding of PR_isIE6 above, and copy and paste the above into Notepad.