您可以使用 Cocoa 的 NSDecimalNumber 类.它不是无限精度，但可以表示精度的 38 位十进制数字，这可能足以满足您的需要.

You can use the NSDecimalNumber class from Cocoa. It is not infinite precision, but it can represent 38 decimal digits of precision, which may be enough for what you need.