How to write 0.9 to the power of 3 (with variables) in Swift

I´m working on a math program in Xcode Command Line Tool and have some troubles writing the maths in coding.

I want the program to to take to variables (p and x) and find the power of them (p^x).

This is my code now:

import Foundation

var x = 3
var p = 0.9

let squared = pow(p, x)

print(squared) 

I get the error: No exact matches in call to global function ‘pow’

Can someone help me solve this ? 😀

>Solution :

You’re running into the issue because the compiler is doing automatic type inference and x and p are inferred to be different types.

Here’s what the compiler infers the types to be:

var x: Int = 3
var p: Double = 0.9

That’s a problem, because there’s no pow function that takes a combination of Int and Double.

Here’s what you probably want:

var x: Double = 3
var p: Double = 0.9

let squared = pow(p, x)

print(squared)

Or, alternately, the compiler can infer x as a Double if you include the decimal:

var x = 3.0
var p = 0.9

In both of the above cases, the compiler uses the pow function that takes Doubles for both arguments.