I am new at swift language and I need to compare some strings or some characters in any string. 

first question:
The last version of swift doesn't allow equal operation == like this.

```
if "1" == item.index(item.startIndex, offsetBy: 7){
     print("ok!")
}

```

item is a string, it has this string "01: 06-08-2017, 13:43" (I can see its inside when I write print)

How can I check some characters in any string?