Convert numbers to and from a custom positional notation.

{{>getting-started}}

Description

Y.AnyBaseConverter is an object that will convert numbers to and from a positional notation with a custom alphabet and base.

Numbers are generally displayed in base ten. This means there are ten single-digit numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9) before the first two-digit number, 10. Sometimes it is useful to work with numbers in other bases. Base 2, base 8, and base 16 tend to come up frequently in programming. JavaScript provides a toString method on numbers which can convert a number to any base from base 2 to base 36 and a parseInt function for converting the strings back into numbers. For bases greater than 10, lower-case letters are used for single digits greater than 9. For example, base 16 uses these single-digit numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, and f.

Y.AnyBaseConverter is very similar to number.toString and parseInt except it can convert to and from bases greater than 36 and use a custom alphabet to represent the single-digit numbers. In addition to any convenient mathematical properties, it may be helpful to convert to a higher base as a simple way to compress a large number as a string or to use a custom alphabet as a method of obfuscation.

More information about positional notation and bases:
http://en.wikipedia.org/wiki/Positional_notation
http://en.wikipedia.org/wiki/Radix

Example

``` YUI().use('gallery-any-base-converter', 'node', function (Y) { var anyBaseConverter, bodyNode = Y.one('body'), number = 1234567890, numberConverted; // By default, Y.AnyBaseConverter comes with a base 64 alphabet which // supports floating-point numbers, negative numbers, and is completely URL // safe. (This is not quite the same thing as base-64 encoding.) bodyNode.append('

Base 64 Alphabet

'); anyBaseConverter = new Y.AnyBaseConverter(); // convert a number to a string numberConverted = anyBaseConverter.to(number); bodyNode.append('

' + number + ' converts to ' + numberConverted + '

'); bodyNode.append('

' + numberConverted + ' converts back to ' + anyBaseConverter.from(numberConverted) + '

'); // // Binary - Used primarily by computer hardware. // bodyNode.append('

Binary Alphabet

'); anyBaseConverter = new Y.AnyBaseConverter({ alphabet: '01' }); numberConverted = anyBaseConverter.to(number); bodyNode.append('

' + number + ' converts to ' + numberConverted + '

'); bodyNode.append('

' + numberConverted + ' converts back to ' + anyBaseConverter.from(numberConverted) + '

'); // // Base 58 - Only uses alphanumeric digits that are easily human readable. // bodyNode.append('

Base 58 Alphabet

'); anyBaseConverter = new Y.AnyBaseConverter({ alphabet: '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz' }); numberConverted = anyBaseConverter.to(number); bodyNode.append('

' + number + ' converts to ' + numberConverted + '

'); bodyNode.append('

' + numberConverted + ' converts back to ' + anyBaseConverter.from(numberConverted) + '

'); // // Confusing - Same base, same characters, different order. // bodyNode.append('

Confusing Base 10 Alphabet

'); anyBaseConverter = new Y.AnyBaseConverter({ alphabet: '8641359207' }); numberConverted = anyBaseConverter.to(number); bodyNode.append('

' + number + ' converts to ' + numberConverted + '

'); bodyNode.append('

' + numberConverted + ' converts back to ' + anyBaseConverter.from(numberConverted) + '

'); // // Large Alphabet - Take care to encode characters correctly! // bodyNode.append('

Large Alphabet

'); anyBaseConverter = new Y.AnyBaseConverter({ alphabet: ' !"#$%&\'()*+,/0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ' }); numberConverted = anyBaseConverter.to(number); bodyNode.append('

' + number + ' converts to ' + numberConverted + '

'); bodyNode.append('

' + numberConverted + ' converts back to ' + anyBaseConverter.from(numberConverted) + '

'); }); ```

Example Output

This example produces the following output.

Base 64 Alphabet

1234567890 converts to 19aWBI

19aWBI converts back to 1234567890

Binary Alphabet

1234567890 converts to 1001001100101100000001011010010

1001001100101100000001011010010 converts back to 1234567890

Base 58 Alphabet

1234567890 converts to 2t6V2H

2t6V2H converts back to 1234567890

Confusing Base 10 Alphabet

1234567890 converts to 6413592078

6413592078 converts back to 1234567890

Large Alphabet

1234567890 converts to !!Ù¼_

!!Ù¼_ converts back to 1234567890