Do you know how to represent exponential power in Swift?

I thought it is using the ^ operator.

If you think so too, you better read on. I failed a coding interview question because I assumed so.

What is the ^ operator?

After the coding session ended, I investigate into what went wrong. Opening Xcode playground, I Alt-click on the ^.

Returns the result of performing a bitwise XOR operation on the two given values.

Oops. It is XOR!

The last time I use XOR was long time ago in my engineering class working on logic board.

What is the exponential power operator?

Turns out, in Foundation framework, there is a pow(_:_).

The first argument has to be a Decimal. So if you have an Int, you could conveniently cast it to Double.

pow(Double(anInt), powerInt)

Anyway, I did use pow before. But my brain just assumed it is ^.

What is Decimal?

In case you didn’t know, Decimal is a more precise type to represent numbers. You will need it in financial calculations so as to represent money precisely (you won’t want the system to round your money)!

Decimal uses more bits than Double, and will be slower.

It can represent numbers precisely because it stores a number as 3 components: the sign, significant, and exponent.




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