How to use println in Swift to format number

Question

When logging-out a float in Objective-C you can do the following to limit your output to only 2 decimal places:

float avgTemp = 66.844322156 NSLog (@"average temp. = %.2f", avgTemp); 

But how do you do this in Swift? And how do you escape other characters in println in Swift?

Here's a regular Swift println statement:

println ("Avg. temp = \(avgTemp)") 

So how do you limit decimal places?

Also, how do you escape double-quotes in println?

Answer 1

Here's the shortest solution I found thus far:

let avgTemp = 66.844322156 println(NSString(format:"%.2f", avgTemp)) 

Its like the swift version of NSString's stringWithFormat

Answer 2

Everything about the format of a number as a string can be adjusted using a NSNumberFormatter:

let nf = NSNumberFormatter() nf.numberStyle = NSNumberFormatterStyle.DecimalStyle nf.maximumFractionDigits = 2 println(nf.stringFromNumber(0.33333)) // prints 0.33 

You can escape quotes with a backslash

println("\"God is dead\" -Nietzsche")