ios - Swift: Regular expression to detect non alpha numeric characters -

i'm trying build regular expression detect string containing alphanumeric characters , special characters haven't found right it. here code:

var str = "asda~dd.asd98asd09asd098asd098ads908" let myregex = "^[a-z]{7}\\.[a-z0-9]{28}$" if (str.rangeofstring(myregex,options: .regularexpressionsearch) != nil) {           str = "itwork.yes"    } 

any of knows how can build regular expression detect non alphanumeric characters ?

i'll appreciate help.

how using rangeofcharacter?

// choose character set , add characters want check besides alphanumeric characters let set = characterset.alphanumerics.union(characterset(charactersin: ".\\"))  // check range of characters in string let range = str.rangeofcharacter(from: set, options: .regularexpression) 

that's 1 of cleanest ways doing this.

edit:

if want detect non-alphanumeric characters, use set.inverse instead of set when calling range function.