final protected function init(string $a, string $b, & $aDig, & $bDig, & $aNeg, & $bNeg) : void
    {
        $aNeg = ($a[0] === '-');
        $bNeg = ($b[0] === '-');

        $aDig = $aNeg ? \substr($a, 1) : $a;
        $bDig = $bNeg ? \substr($b, 1) : $b;
    }
final protected function init(string $a, string $b, & $aDig, & $bDig, & $aNeg, & $bNeg) : void
    {
        $aNeg = ($a[0] === '-');
        $bNeg = ($b[0] === '-');

        $aDig = $aNeg ? \substr($a, 1) : $a;
        $bDig = $bNeg ? \substr($b, 1) : $b;
    }
final protected function init ( string $ a , string $ b , & $ aDig , & $ bDig , & $ aNeg , & $ bNeg ) : void { $ aNeg = ( $ a [ 0 ] === '-' ) ; $ bNeg = ( $ b [ 0 ] === '-' ) ; $ aDig = $ aNeg ? \ substr ( $ a , 1 ) : $ a ; $ bDig = $ bNeg ? \ substr ( $ b , 1 ) : $ b ; }
Extracts the digits and sign of the operands.

@param string $a    The first operand.
@param string $b    The second operand.
@param string $aDig A variable to store the digits of the first operand.
@param string $bDig A variable to store the digits of the second operand.
@param bool   $aNeg A variable to store whether the first operand is negative.
@param bool   $bNeg A variable to store whether the second operand is negative.

@return void
Extracts the digits and sign of the operands .