Swift: Developing iOS Applications

Handling errors

If we try to call a function, such as normal, Swift is going to give us an error, as shown in the following example:

let repeated1 = repeatString("Hello", untilLongerThan: 20)
// Error: Call can throw but is not market with 'try'

To eliminate this error, we must add the try keyword before the call. However, before we move forward, I would recommend that you wrap all of your code inside a function, if you are following along in a playground. This is because throwing errors at the root level of a playground will not be handled properly and may even cause the playground to stop working. To wrap your code in a function, you can simply add the following code:

func main() {
// The rest of your playground code
}
main()

This defines a function ...