Is operator for type checking in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if variable 'item' is of type String.

Swift

if item [1] String {
    print("It's a string")
}

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

A==

Bas

Cis

Dinstanceof

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'as' instead of 'is' for type checking.

The is operator checks if a variable is of a certain type in Swift.

2fill in blank

medium

Complete the code to check if 'value' is an Int before casting.

Swift

if value [1] Int {
    let number = value as! Int
    print(number)
}

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

Ais

Bas

C==

Dinstanceof

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'as' instead of 'is' for checking type.

Use is to check type before force casting with as!.

3fill in blank

hard

Fix the error in the code to check if 'obj' is a Double.

Swift

if obj [1] Double {
    print("Double value")
}

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

Ais

Binstanceof

C==

Das

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'as' instead of 'is' causes a compile error.

The is operator is used for type checking in Swift, not as.

4fill in blank

hard

Fill both blanks to check if 'element' is a String and then cast it safely.

Swift

if element [1] String {
    if let str = element [2] String {
        print(str)
    }
}

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

Ais

Bas?

Cas!

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'as!' for casting without checking type first.

Use is to check type and as? for safe casting.

5fill in blank

hard

Fill all three blanks to check if 'data' is an Int, cast it safely, and print it.

Swift

if data [1] Int {
    if let number = data [2] Int {
        print(number [3] 10)
    }
}

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

Ais

Bas?

C+

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'as!' without checking type, or using wrong operator for addition.

Check type with is, safely cast with as?, then add 10 with +.