swift – 将unichar转换为String？

我从Nsstring的实例方法characteratIndex(Int)返回一个unichar类型,我想将它与 Swift类型的String进行比较.是否有捷径可寻？

var str = "#ffffff"
var unichar = (str as Nsstring).characteratIndex(0)
var unicharString = // Perform magic
var containsHash = unicharString == "#" // Should return `true`

谢谢

var str:String = "#ffffff"
var unichar = str[str.startIndex]
var unicharString = "\(unichar)"
var containsHash = unicharString == "#"