encrypt with T9 mode for SMS messages

Question

i was working today then i got this idea. I want to make a script that take a plain text and then encrypt it with T9 mode for SMS messages on mobile phone.

plain text : Hello

Result : 4433555555666

So i created some class like this :

<?php

class decoder {

public $keys = array(
                '2' => 'abc',
                '3'=> 'def',
                '4'=> 'ghi',
                '5'=> 'jkl',
                '6'=> 'mno',
                '7'=> 'pqrs', 
                '8'=> 'tuv', 
                '9'=> 'wxyz',
                '0'=> ' '
                );



    function key($string) {

        // store every character from the string into an array
        $str = str_split($string);


    }




}   

$deco = new decoder;

echo $deco->key('hello');
?>

the problem is i need some algorithms and lines on how i can compare every character from the given plain text with the keys array and then return a key number if there a match.

In general it's a good practice to add the result you got with your code — Shir Gans, Sep 08 '19 at 13:33
@ShirGans do you think that this script is a good idea to put it on github if it's working ? — Alex, Sep 08 '19 at 13:38

score 2 · Answer 1 · answered Sep 08 '19 at 13:41

2

You can always make this simpler, since you write it only once, you can use this:

$keys = array(
'a' => '2',
'b' => '22',
'c' => '222'... //and so on

and then use simple string replace.

Otherwise you can continue your code, but I think it will be not very optimized for performance, since you will need to loop through your array multiple times to find the given char.

answered Sep 08 '19 at 13:41

Shir Gans

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this goes against code optimization but i think it's okay, i'll start with this to make it works after that i will dosome changes xD – Alex Sep 08 '19 at 13:48

score 2 · Accepted Answer · answered Sep 08 '19 at 14:33

<?php

class decoder {

    public $keys = array(
                'a' => '2',
                'b'=> '22',
                'c'=> '222',
                'd'=> '3',
                'e'=> '33',
                'f'=> '333', 
                'g'=> '4', 
                'h'=> '44',
                'i'=> '444',
                'j'=> '5',
                'k'=> '55',
                'l'=> '555', 
                'm'=> '6',
                'n'=> '66',
                'o'=> '666', 
                'p'=> '7',
                'q'=> '77',
                'r'=> '777', 
                's'=> '7777',
                't'=> '8',
                'u'=> '88',
                'v'=> '888',
                'w'=> '9',
                'x'=> '99',
                'y'=> '999', 
                'z'=> '9999',
                ' '=> '0'
                );

    function key($string) {

        // store every character from the string into an array
        $char = str_split($string);

        $i = 0;
        while ($i<count($char)) {

            //foreach all keys and values
            foreach ($this->keys as $key => $key_value) {

                if ($char[$i] == $key) {
                    echo $key_value;
                }
            }

            $i++;
        }

    }

}   

$deco = new decoder;

echo $deco->key('hello');
?>

encrypt with T9 mode for SMS messages

2 Answers2