Raise NSDecimalNumber to Negative Power

Question

I need the equivalent of the C pow () function, which will work with NSDecimalNumbers. With pow, you can use negative numbers, for example. pow(1514,-1234), with the NSDecimal decimalNumberByRaisingToPower: method, you are forced to use the NSUInteger, which seems to require a positive value.

I would like to do something like this:

[decimalNumber decimalNumberByRaisingToPower:-217.089218];

or

[decimalNumber decimalNumberByMultiplyingByPowerOf10:-217];

no failures due to overflow or overflow exceptions.

Answer 1

Mathematically a ^ (- b) == 1 / (a ​​^ b). Therefore, if you just need to raise to negative integrated power,

decimalNumber = [decimalNumber decimalNumberByRaisingToPower:1234];
decimalNumber = [[NSDecimalNumber one] decimalNumberByDividingBy:decimalNumber];

, , (1) pow() (2) ( ).

Answer 2

, , , decimalNumberByRaisingToPower, Apple:

(NSDecimalNumber *) decimalNumberByMultiplyingByPowerOf10: ()

.

Answer 3

decimalNumber doubleValue, pow ++. , , . . Objective-C ++? ++ c.