Online PHP editor | output for iWBC0

<?php /** * Immutable class for handling numbers with precision. * * Never change the $number or the $precision after the creation of the object. */ class DecimalNumber { private $precision; private $number; /** * Get an instance given a string and a precision * @param string $string The decimal number in string form * @param int $precision The precision of the number * @return DecimalNumber Return new instance */ public static function createWithString($string, $precision = 4) { $me = get_called_class(); $number = new $me; $number->precision = $precision; $number->number = bcadd($string, '0', $precision); return $number; } /** * Perform an addition operation * @param DecimalNumber $number the number to add * @return DecimalNumber Return the sum */ public function add(DecimalNumber $number) { return DecimalNumber::decimalNumberWithString(bcadd($this->number, $number, $this->precision)); } /** * Automagically convert to a string * @return string returns a string containing the value of this DecimalNumber */ public function __toString() { return $this->number; } } $d = DecimalNumber::createWithString('.7'); echo $d->add(DecimalNumber::createWithString('.1');