Learn
We can provide a type annotation when we declare a variable to be clear about the kind of value that the variable can store.
Some of the basic data types:
Int
: integer numbersDouble
: floating-point numbersString
: a sequence of charactersBool
: true/false values
Type annotations begin with a colon :
and end with a type.
To declare a variable named artist
and give it the type String
:
var artist: String
It explicitly specifies the type of a variable to be String
, so now we can only give artist
text string values:
artist = "Daniel Johnston"
We can also write the above code in one line:
var artist: String = "Daniel Johnston"
Note: Swift is known as a strongly typed language. If you try to give an integer variable a decimal value, you are going to get unexpected results, warnings, or errors.
Instructions
1.
Declare a String
variable named book
with a value of "Just Kids"
.
2.
Declare an Int
variable named pageCount
with a value of 278
.
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