[swift] 数字を３桁区切り＋小数点第２位まで表示させる

数字を３桁区切り＋小数点第２位まで表示させる

サンプルコード：

func numFormatter(num:Float)->String{
    let formatter = NSNumberFormatter()
    formatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
    formatter.groupingSeparator = ","
    formatter.groupingSize = 3 //3桁に区切る
    formatter.maximumFractionDigits = 2
    formatter.positiveFormat = "0.00"
    formatter.roundingMode = NSNumberFormatterRoundingMode.RoundHalfUp // 四捨五入
    
    return formatter.stringFromNumber(num)!
}

let pi = 3.14159265359
let largePi = Float(pi*1000)
let str = numFormatter(largePi)
print(str) //3,141.59