swift - Strings in Switch Statements: 'String' does not conform to protocol 'IntervalType'

Question

I am having problems using strings in switch statements in Swift.

I have a dictionary called opts which is declared as <String, AnyObject>

I have this code:

switch opts["type"] {
case "abc":
    println("Type is abc")
case "def":
    println("Type is def")
default:
    println("Type is something else")
}

and on the lines case "abc" and case "def" I get the following error:

Type 'String' does not conform to protocol 'IntervalType'

Can someone explain to me what I am doing wrong?

question from:https://stackoverflow.com/questions/26865132/strings-in-switch-statements-string-does-not-conform-to-protocol-intervaltyp

Answer 1

This error is shown when an optional is used in a switch statement. Simply unwrap the variable and everything should work.

switch opts["type"]! {
  case "abc":
    println("Type is abc")
  case "def":
    println("Type is def")
  default:
    println("Type is something else")
}

Edit: In case you don't want to do a forced unwrapping of the optional, you can use guard. Reference: Control Flow: Early Exit