` operator. * * @param mixed $other * * @return int 0 if this decimal is considered is equal to $other, * -1 if this decimal should be placed before $other, * 1 if this decimal should be placed after $other. */ public function compareTo($other): int {} /** * String representation. * * This method is equivalent to a cast to string, as well as `toString`. * * @return string the value of this decimal represented exactly, in either * fixed or scientific form, depending on the value. */ public function __toString(): string {} /** * JSON * * This method is only here to honour the interface, and is equivalent to * `toString`. JSON does not have a decimal type so all decimals are encoded * as strings in the same format as `toString`. * * @return string */ public function jsonSerialize() {} }