Combination pairs of currencies

[silkfire]

Hey all I've found some combination functions out there but they're not working really like I want.

 

I have an array with some currencies:

 

array('SEK', 'EUR', 'USD', 'GBP', 'DKK', 'NOK', 'ISK');

 

Now I want the function to generate an array with all possible pairs:

 

array(array('SEK', 'EUR'), array('SEK', 'USD') ...)

 

It must allow for the inverse form: EUR, SEK is different from SEK, EUR.

 

But trash all pairs that are equal: SEK, SEK or EUR, EUR.

 

Help me out?

[Adam]

Not sure I understand how US dollars can be considered a "pair" with Swedish kronor?

 

Edit

 

Sorry, just realised what you meant. Will reply again in a few minutes..

[Adam]

It's a little loopy, but this appears to work:

 

// Loop through each currency
foreach ($currencies as $currency)
{
    // Loop through the currencies again to access the others
    foreach ($currencies as $other_currency)
    {
        // Check it's not the same
        if ($currency == $other_currency)
        {
            continue;
        }

        // Check this pair doesn't already exist
        foreach ($currency_pairs as $currency_pair)
        {
            if (($currency_pair[0] == $currency && $currency_pair[1] == $other_currency)
             || ($currency_pair[1] == $currency && $currency_pair[0] == $other_currency))
            {
                continue 2;
            }
        }

        // Add to pairs array
        $currency_pairs[] = array($currency, $other_currency);
    }
}

print_r($currency_pairs);

 

Edit.. again

 

I've actually written that so EUR - SEK, and SEK - EUR are classed as the same. To treat them differently, change the IF to this:

 

            if ($currency_pair[0] == $currency && $currency_pair[1] == $other_currency)
            {
                continue 2;
            }

 

Edit.. again.. again

 

Ha.. actually you can just remove the entire foreach loop there if that's the case.. the same order will never come up twice.

[silkfire]

Oh thank you Adam! So you figured it out? I needed a table for currency conversion but let PHP generate all the combos (much faster, eh?). Thanks!