Data types (Int, Double, String, Bool) in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an Int in Swift?

An Int is a data type that stores whole numbers without decimals, like 5 or -10.

beginner

How does Double differ from Int?

Double stores numbers with decimals, like 3.14, while Int stores whole numbers only.

beginner

What kind of values does Bool hold?

Bool holds only two values: true or false. It is used for yes/no or on/off decisions.

beginner

What is a String in Swift?

String is a data type that stores text, like words or sentences, for example: "Hello" or "Swift".

intermediate

Why is it important to use the correct data type in Swift?

Using the correct data type helps the app use memory efficiently and prevents errors by making sure data is handled properly.

Which Swift data type would you use to store the number 42?

A Bool

B Int

C String

D Double

42 is a whole number, so Int is the correct data type.

Which data type can hold the value 3.14159?

A Double

B Int

C Bool

D String

Double stores decimal numbers like 3.14159.

What value can a Bool variable hold?

A Any number

B Text only

C true or false

D Decimal numbers

Bool holds only true or false.

Which data type would you use to store the word "Hello"?

A String

B Bool

C Int

D Double

String stores text like "Hello".

Why should you choose the right data type in Swift?

A To make the app slower

B It does not matter

C To confuse other developers

D To use memory efficiently and avoid errors

Correct data types help the app run smoothly and prevent mistakes.

Explain the difference between Int and Double in Swift.

Think about numbers with and without decimals.

Describe when you would use a Bool and a String in an app.

Consider yes/no questions and words.