如何用科学记数法表示NSNumber？

Question

I use [NSNumber numberWithDouble:] method to form my NSNumber. However, since some of the values might be large, I want to know if there is a way to tell NSNumber to represent itself with the scientific notation. Thanks in advance!

Answer 1

Take a look at NSDecimalNumber . They allow for higher precision than NSNumber , and support scientific notation and other features.

Answer 2

Try turning the number into as string and use the scientific print formatter %e , or %E

I say this because there is no point in trying to get the NSNumber to format itself because it is only an object wrapper around a value. When you want to present the number, then treat it as a string and use the NSString methods to show the value in the way that you want.