iOS Swift. Show two decimal places for Double

We can format output for double values with String Format:

let value = 3.1415
let formatValue = String(format:"%.2f", value) // 3.14

Or we can use NumberFormatter Class (setting min and max number of digits after decimal separator):

let formatter = NumberFormatter()
formatter.numberStyle = NumberFormatter.Style.decimal
formatter.roundingMode = NumberFormatter.RoundingMode.halfUp
formatter.maximumFractionDigits = 2
formatter.minimumFractionDigits = 2
        
let roundedValue1 = formatter.string(from: 0.684) // 0.68
let roundedValue2 = formatter.string(from: 0.687) // 0.69
let roundedValue3 = formatter.string(from: 0.600) // 0.60