Swift-字符串字符是否唯一

题目:字符串中所有字符是否全不相同.

` func isUniqueChar(str:String)->Bool {
 
 
    if str.characters.count > 256 {
        return false
    }
    
    var chars:[Bool] = [Bool].init(repeating: false, count: 256)
    
    for i in 0..

测试代码:

`var uniqueStr:String = "FlyElephant"
 
 
var isUnique:Bool = myString.isUniqueChar(str: uniqueStr)
 
 
print("(uniqueStr)---是不是所有字符串唯一:(isUnique)")`