如何拆分PHP并重用其中的一部分？

Question

I'm trying to split a line of PHP up, the reason being I don't actually always need some of the code and so that I can reuse parts of it.

The main reason I'm doing this is because the currency I get shows more digits for some currencies eg 1.2562 instead of 1.25, so I want to use the substr function only on certain GET's and be able to modify it for other GET's.

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symbol is always required, substr isn't, $converter always required, end part of substr isn't however it can change, new currency is required.

$symbol[2] . substr(($converter->convert($defaultCurrency, $newCurrency) * 1),  0, 4) . " <b>" .$newCurrency. "</b>";

I've tried doing this with explode, however I'm not entirely sure how to do it as I have never really had to split anything up before so I'm a little puzzled on how to go about it.

Once the code has gone through the GET checking which is the current one set, I want it to grab the specified split up code pieces and then output it.

Answer 1

Put your code in a function like this:

function formatCurrency($symbol, $converter, $defaultCurrency, $newCurrency, $factor=1.0, $suffix="", $substrChars=0) {
    if($substrChars>0) {
        return $symbol . substr(($converter->convert($defaultCurrency, $newCurrency) * $factor),  0, $substrChars) . $suffix . " <b>" . $newCurrency. "</b>";
    } else {
        return $symbol . ($converter->convert($defaultCurrency, $newCurrency) * $factor) . $suffix . " <b>" . $newCurrency. "</b>";
    } 
}

If you call it without the $substrChars parameter, it will omit the substr() call, otherwise it will strip all but the first $substrChars characters:

if( $_GET['currency'] === "GBP" ){
    $newCurrency = $_GET['currency'];
    $string = formatCurrency($symbol[1], $converter, $defaultCurrency, $newCurrency, 2.0, ".00", 0);
} elseif( $_GET['currency'] === "USD" ){
    $newCurrency = $_GET['currency'];
    $string = formatCurrency($symbol[2], $converter, $defaultCurrency, $newCurrency, 1.0, "", 4);
}

This solution is very readable because you immediately see the difference between the two branches in the conditional statement.