将功能与不同的呼叫方法结合起

Question

I have 2 functions

This one generates numbers only

//Generate a string of only numbers.
function GenerateNUM($length)
{
    $alphabet = '1234567890';
    $tip = array();
    $alphaLength = strlen($alphabet) - 1;
    for ($i = 0; $i < $length; $i ++) {
        $n = rand(0, $alphaLength);
        $tip[] = $alphabet[$n];
    }
    return implode($tip);
}

This one generates numbers and letters

//Generate a string of numbers and letters.
function GenerateAll($length)
{
    $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
    $pass = array();
    $alphaLength = strlen($alphabet) - 1;
    for ($i = 0; $i < $length; $i ++) {
        $n = rand(0, $alphaLength);
        $pass[] = $alphabet[$n];
    }
    return implode($pass);
}

and I call it like this

$ValidationCode = GenerateNUM(12);

or this

$ValidationCode = GenerateAll(12);

It works great but my question is do I really need 2 blocks of code? is there a way to create one function and be able to decide if numbers and letters are called or just numbers? or am I over thinking it?

Answer 1

Example of a combined singular function based off your code:

function GenerateCode($length,$type='ALPHA')
{
    $alphabet = (($type == 'ALPHA')?'ABCDEFGHIJKLMNOPQRSTUVWXYZ':'') .'1234567890';
    $code = array();
    $alphaLength = strlen($alphabet) - 1;
    for ($i = 0; $i < $length; $i ++) {
        $n = rand(0, $alphaLength);
        $code[] = $alphabet[$n];
    }
    return implode($code);
}

$ValidationCode = GenerateCode(12,'NUM');// just makes a numbers only code
$ValidationCode = GenerateCode(12,'ALPHA');// makes an alphanumeric code

---

But there is nothing wrong with multiple small utility functions though. The naming keeps them clean and obvious their intent. However if you have a LOT of duplicated code between a bunch of utility functions, then you can combine them with a second parameter and adjusting small pieces inside based on that param (like above).

---

A slightly better example of generating a random string like your function (includes upper and lower case lettering):

function GenerateCode($length,$type='ALPHA')
{
    $string = '';
    for ($n=1; $n <= $length; $n++) {
        if ($type == 'NUM') {
            $string .= mt_rand(0,9);
        } else {
            $randnum = mt_rand(0,61);
            $string .= ( ($randnum < 10) ? chr($randnum+48) :  // number chr 48 - 57
                        (($randnum < 36) ? chr($randnum+55) :  // upperletter chr 65 - 90
                                           chr($randnum+61) ));// lowerletter chr 97 - 122
        }
    }
    return $string;
}

// example GenerateCode(12,'ALPHA') output: XNu1n833b2ox