Closure in PHP 7.1 examples

gistfile1.txt

<?php
function writeln($line_in) {
    echo $line_in." \n";
}

class Test {
    public $number;
    
    function __construct(int $number)
    {
        $this->number  = $number;
    }

    public function getNumber(): int
    {
        return $this->number;
    }
    
    public function multiplyStatically(): int
    {
        return $this->number * 2;
    }
    
    public function multiplyWithParams(int $multiplicator): int
    {
        return $this->number * $multiplicator;
    }
}


$test = new Test(2);

writeln('START');
writeln('');

writeln('Context 1 - Raw number');
writeln($test->getNumber());
writeln('');

$cl1 = \Closure::fromCallable([$test, 'multiplyStatically']);
writeln('Context 2 - static multiply number');
writeln($cl1->call($test));
writeln('');

$cl2 = \Closure::fromCallable([$test, 'multiplyWithParams']);
writeln('Context 3 - Multiply number by multiplicator');
writeln($cl2->call($test, '9'));
writeln('');

writeln('END');