code a number into letters

Question

Lets say I have something like 97463

I want to code it into letters say kljhs

I'm using php/javascript at the moment, but I guess its a universal problem.

Whats the most efficient way to do this in a way thats reversible?

(reversible meaning given numbers I can make the letter code and then later given just the number code I can return the letters)

By what logic do you want to do the encoding? A=1, B=2...? – Pekka Jan 20 '11 at 10:54 — Pekka, Jan 20 '11 at 10:54

score 2 · Accepted Answer · answered Jan 20 '11 at 10:57

2

You could just use the strtr function

$input = '123456';
$output = strtr($input, '0123456789', 'abcdefghij');

To reverse, use

$input = 'bcdefg';
$output = strtr($input, 'abcdefghij', '0123456789');

answered Jan 20 '11 at 10:57

Dogbert

The opther solution is faster, but this gives more control. I like! – David19801 Jan 20 '11 at 11:15

score 0 · Answer 2 · answered Jan 20 '11 at 10:56

You can use dechex() to encode the number as hexadecimal, and hexdec() to reverse:

$hex = dechex(97463); // "17cb7"
$dec = hexdec($hex);  // 97463

Alternatively you may want to use base_convert(), to convert to an arbitrary base from 2 to 36 :

$enc = base_convert(97463, 10, 36);  // "237b"
$dec = base_convert("237b", 36, 10); // 97463

2 Answers2