base 36 () functions in various languages

notes-base36

# php
<?php print base_convert("12abcxyz",36,10); ?>
----
#python
def base36encode(number, alphabet='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'):
    """Converts an integer to a base36 string."""
    if not isinstance(number, (int, long)):
        raise TypeError('number must be an integer')
 
    base36 = ''
    sign = ''
 
    if number < 0:
        sign = '-'
        number = -number
 
    if 0 <= number < len(alphabet):
        return sign + alphabet[number]
 
    while number != 0:
        number, i = divmod(number, len(alphabet))
        base36 = alphabet[i] + base36
 
    return sign + base36
 
def base36decode(number):
    return int(number, 36)
 
print base36encode(1412823931503067241)
print base36decode('AQF8AA0006EH')
----
# javascript
(1234567890).toString(36)  // => "kf12oi"
parseInt("kf12oi",36) // => 1234567890
----
SOURCE: http://en.wikipedia.org/wiki/Base_36
----
# math example
(FACE)36 = 15*363 + 10*362 + 12*36 + 14.
SOURCE: http://primes.utm.edu/notes/words.html

USES IN PRACTICE:
tinyurl -- use base 36 integers as compact alphanumeric identifiers
reddit -- uses base-36 for identifying posts and comments.

INTERESTING
http://primes.utm.edu/notes/words.html - prime numbers that are words in Base36
WIKIPEDIA (Base36) == 91,730,738,691,298 (decimal)