calling specific index to add a function for that index : I have a liquidfloatingactionbutton and the way you add an action is a didselectitematindex function but how can I call certain indexes to add different function to each different index. This is what I have so far but the error I get is "cannot assign to value: 'index' is a 'let' constant". 

    func liquidFloatingActionButton(_ liquidFloatingActionButton: LiquidFloatingActionButton, didSelectItemAtIndex index: Int) {
        print("did Tapped! \(index)")
        
        if index = "0"{
            print("Buy")
        }else if index = "1"{
            print("Trade")
        }else if index = "2"{
            print("Save")
        }else if index = "3"{
            print("Message")
        }else if index = "4"{
            print("Directions")
        }
        
        liquidFloatingActionButton.close()
    }