Type Annotation in Swift

Written by Team Kodeco

In Swift, you can explicitly specify the data type of a variable or constant using type annotations. A type annotation is a way to specify the type of a variable or constant by adding a colon followed by the type name after the variable or constant name.

For example, to declare a variable as a string, you can use the following syntax:

var message: String = "Hello, World!"

In this example, message is a variable of type String that has been set to the value “Hello, World!”.

Similarly, you can use type annotations to declare a constant as an integer:

let numberOfApples: Int = 5

In this example, numberOfApples is a constant of type Int that has been set to the value 5.

You can think of type annotation like putting a label on a box: The label tells you what the box contains.