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iOS Swift Functions and Optionals Optionals What is an Optional?

Posted by Anthony Boyd
Anthony Boyd
1,047 Points

I don't get how to solve this question on optionals

The search function below returns a name if it is found in the array and an empty string if it is not found. Modify the search function to return an optional instead of just a String. In addition, you have to make sure the function returns a nil if the name is not found in the array.

How do you do this task

3 Answers

Micahyah Hawkins
Micahyah Hawkins
3,496 Points
Micahyah Hawkins
Micahyah Hawkins
3,496 Points

Hello Anthony

To make the return value optional you need to add a ? to the end of the return value:

func search(#name: String) -> String? {

Now once it is an optional you have the rest of the function as normal. With the for and if statements if it the name is found it will return the name. Though if it does not find the name it will drop out of the if and for statement and execute the ending return statement. In the example it currently returns "" but the question states to return nil. So you will change the "" to nil. Please see below.

func search(#name: String) -> String? { let names = ["Doc","Grumpy","Happy","Sleepy","Bashful","Sneezy","Dopey"] for n in names { if n == name { return n } } return nil }

So to recap on the first line of the fund you add the ? to the return value String.

Then if it does not find a name you change the empty string "" to nil

I hope this helps

Laurentiu Szabo
Laurentiu Szabo
1,870 Points
Laurentiu Szabo
Laurentiu Szabo
1,870 Points 
func search(#name: String) -> String? {
    let names = ["Doc","Grumpy","Happy","Sleepy","Bashful","Sneezy","Dopey"]
    for n in names {
        if (n == name){          
            return name
        }
    }
    return nil
}
if let person = search(name: "Doc") {

    println("\(person) was found")
}
Benjamin Jones
Benjamin Jones
2,269 Points
Benjamin Jones
Benjamin Jones
2,269 Points

Mine is working in Xcode but not in the browser.. surprise surprise!!

func search(#name: String) -> String? { let names = ["Doc","Grumpy","Happy","Sleepy","Bashful","Sneezy","Dopey"] for n in names { if n == name { return n } } return "nil" }

search(name: "Snow White") - // added this in to test it in Xcode and returns "nil"