Guard let for early exit in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to unwrap the optional value using guard let.

Swift

func printName(name: String?) {
    guard [1] = name else {
        print("No name provided.")
        return
    }
    print("Name is \(unwrappedName)")
}

Drag options to blanks, or click blank then click option'

Avar name

Blet unwrappedName

Clet name

Dvar unwrappedName

Attempts:

3 left

💡 Hint

Common Mistakes

Using var instead of let in guard let statement.

Not unwrapping the optional before use.

Trying to unwrap with the same variable name.

Using guard let unwrappedName = name unwraps the optional name safely for use inside the function.

2fill in blank

medium

Complete the code to unwrap the optional and print the unwrapped value.

Swift

func greet(user: String?) {
    guard let name = [1] else {
        print("User not found.")
        return
    }
    print("Hello, \(name)!")
}

Drag options to blanks, or click blank then click option'

Aname

Bself.user

Cuser

DoptionalUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using the unwrapped variable name on the right side instead of the optional.

Using a variable that does not exist in the scope.

The optional user is unwrapped using guard let name = user to safely access its value.

3fill in blank

hard

Fix the error in the guard statement to unwrap the optional correctly.

Swift

func checkAge(age: Int?) {
    guard let age = [1] else {
        print("Age is missing.")
        return
    }
    print("Age is \(age)")
}

Drag options to blanks, or click blank then click option'

Aage

BoptionalAge

Cself.age

Dnil

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable that is not defined in the function.

Using nil instead of the optional variable.

The optional parameter age must be unwrapped by using its own name in the guard statement.

4fill in blank

hard

Fill both blanks to unwrap the optional and check if the unwrapped value is greater than 18.

Swift

func verify(age: Int?) {
    guard [1] = age, [2] > 18 else {
        print("Access denied.")
        return
    }
    print("Access granted.")
}

Drag options to blanks, or click blank then click option'

Alet unwrappedAge

Bage

CunwrappedAge

Dlet age

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same variable name for unwrapping and condition incorrectly.

Not unwrapping before comparing.

First, unwrap the optional with let unwrappedAge = age. Then check if unwrappedAge > 18 to allow access.

5fill in blank

hard

Fill all three blanks to unwrap two optionals and check if the unwrapped user is a non-empty string.

Swift

func validate(user: String?, password: String?) {
    guard [1] = user, [2] = password, ![3].isEmpty else {
        print("Invalid input.")
        return
    }
    print("User and password are valid.")
}

Drag options to blanks, or click blank then click option'

Alet unwrappedUser

Blet unwrappedPassword

CunwrappedPassword

DunwrappedUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong variable names in the condition.

Not unwrapping both optionals before checking.

Unwrap user and password with let unwrappedUser = user and let unwrappedPassword = password. Then check if unwrappedUser is not empty.