String to Int conversion?

[Black_Hobbit]

I've got a quick question. Is there a way to convert a single character like H or J to a 2 digit number (as an interger)?

[vallette]

Use 'ord'

//Get the ascii number for 'J'
$value=ord('J');

[Black_Hobbit]

That's not what I ment. I ment a TWO digit number. Like 10,12,56,32. Perhaps like A might be 01 and B might be 02 and Z might be 24.

[drawmack]

Look at http://www.asciitable.com and you'll note that uppercase letters use the ascii number in the range of 65 - 90 and lowercase letters use the ascii numbers 97 - 122.

With that information it is easy to accomplish the task:

<?php
// Step 1: let's do it in a function that can just be called
function chr_to_int($chr) {
    // Step 2: validate the input
    $int = ord($chr);
    if($int < 65 || ($int > 90 && $int < 97) || $int > 122) {
       return 0;
    } //end if

// Step 3: Process an uppercase character
if($int < 97) {
    return ($int - 65);
// Step 4: Process a lowercase character
} else {
    return ($int - 97);
} //end if
} //end chr_to_int
?>

[BuzzLY]

realize, however, that if you want "01" to represent "A", you cannot use an integer. Integers never start with 0. If you need the two digits, use a string type, and convert them to integers only when you need to do some sort of math problem.

[Black_Hobbit]

Ok, well, just in case anyone else comes along who is trying to figure this out, this is what I've done (this was before all of you posted):

<?php

//for my purposes this would be inputed 
//through the user so it could be either a capital or 
//lowercase 
$my_letter = "A"; 

//makes the string lowercase
$my_letter = srtolower($my_letter);

//make a number (I could be doing this the 
//hard way but at least it works!)

switch ($my_letter) {
      case "a": 
           $my_letter = 01;
           break;
      case "b":
           $my letter = 02;
           break;
      case "c":
           $my_letter = 03;
           break;
//and so on...

?>

thanks everyone!

[drawmack]

Buzz, you can fix that with sprintf when necessary.

Hobbit,
That is a horrible solution please see my previous solution using the ascii values.

[BuzzLY]

Yes, of course, [man]sprintf[/man]. Now, if there were only a simple way to convert the ascii value of a lowercase letter to it's numerical place in the alphabet... do you think there's an available function in PHP for that? 😉

Hobbit, instead of your select...case statement, try this:

$alpha = ord(strtolower($my_letter)) - 96;