Swift: String from float without rounding the values

Question

1. It is recommended to round the decimals but i am facing an scenario where i just need to cut down the precision.

2. Output: 15.96 to 16.0

3. Desired output: 15.96 to 15.9

Codes:

var value: AnyObject = dict.valueForKey("XXX")!
  var stringVal = NSString(format:"%.1f", value.floatValue)

I thought this will be simple but found tricky. Your thoughts on this is highly appreciated.

Answer 1

Use a NSNumberFormatter and configure its rounding mode accordingly:

let formatter = NSNumberFormatter()
formatter.maximumFractionDigits = 1
formatter.roundingMode = .RoundDown
let s = formatter.stringFromNumber(15.96)
// Result: s = "15.9"