PHP code example of petrknap / optional

1. Go to this page and download the library: Download petrknap/optional library. Choose the download type require.

2. Extract the ZIP file and open the index.php.

3. Add this code to the index.php.

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

petrknap / optional example snippets


namespace PetrKnap\Optional;

/** @var Optional<string> $optionalString */
$optionalString = Optional::of('data');
if ($optionalString->isPresent()) {
    echo $optionalString->get();
}

OptionalResource::ofFalsable(tmpfile())->ifPresent(function ($tmpFile): void {
    fwrite($tmpFile, 'data');
    fclose($tmpFile);
});


namespace PetrKnap\Optional;

class YourClass {}

/**
 * @extends OptionalObject<YourClass>
 */
class YourOptional extends OptionalObject {
    protected static function getInstanceOf(): string {
        return YourClass::class;
    }
}
TypedOptional::register(YourOptional::class); // optional recommended step

function your_strong_typed_function(YourOptional $input): YourOptional {
    return YourOptional::empty();
}

/**
 * @param Optional<YourClass> $input
 * @return Optional<YourClass>
 */
function your_weak_typed_function(Optional $input): Optional {
    return YourOptional::empty();
}