In computer programming, data types specify the type of data that can be stored inside a variable. For example,
var num: Int
Here, Int
is a data type that specifies that the num
variable can only store integer data.
There are six basic types of data types in Swift programming.
Swift Data Types
Data Types | Example | Description |
---|---|---|
Character |
"s" ,"a" |
a 16-bit Unicode character |
String |
"hello world!" |
represents textual data |
Int |
3 , -23 |
an integer number |
Float |
2.4 , 3.14 , -23.21 |
represents 32-bit floating-point number |
Double |
2.422342412414 |
represents 64-bit floating-point number |
Bool |
true and false |
Any of two values: true or false |
Swift Character
The character data type is used to represent a single-character string. We use the Character
keyword to create character-type variables. For example,
// create character type variable
var letter: Character = "s"
print(letter)
// Output: s
In the above example, we have created a Character
type variable named letter
. Here, we have assigned "s"
to the letter
.
Note: If you try to assign more than one character like "abc" to variables of Character
type, you'll get an error message.
Swift String
The string data type is used to represent textual data.
We use the String
keyword to create string-type variables. For example,
// create string type variable
var language: String = "swift"
print(language)
// Output: swift
In the above example, we have created a String
type variable named language
. Here, we have assigned "swift"
to the language
.
To learn more about strings and characters, visit Swift Characters and Strings.
Swift Integer
An integer data type is used to represent a whole number with no fractional component. We use the Int
keyword to create integer-type variables. For example,
// create integer type variable
var number: Int = 3
print(number)
// Output: 3
In the above example, we have created an Int
type variable named number
. Here, we have assigned 3
to the number
.
Here are some of the basic properties of integers in swift programming.
- Size: Depends on the platform type
- Range: -231 to 231-1 (32 bit platform)
-263 to 263-1 (64-bit platform)
Variants of Int type
Swift programming provides different variants of Int
type having different sizes.
Variant | Size | Range |
---|---|---|
Int8 | 8 bit | -128 to 127 |
Int16 | 16 bit | -215 to 215-1 |
Int32 | 32 bit | -231 to 231-1 |
Int64 | 64 bit | -263 to 263-1 |
UInt | Depends on platform | 0 to 232(32-bit platform) 0 to 264(64-bit platform) |
Swift Boolean
A boolean data type is used to represent logical entities. It can have one of two values: true
or false
. We use the Bool
keyword to create boolean-type variables. For example,
// create boolean type variable
let passCheck: Bool = true
print(passCheck)
let failCheck: Bool = false
print(failCheck)
Output
true false
In the above example, we have created Bool
type variables: passCheck and failCheck. Here, we have assigned true
to the passCheck variable and false
to the failCheck variable.
If we don't assign any value to a boolean variable, it takes false
as its default value.
Note: Booleans are frequently used with if-else
statements. To learn more, visit Swift if...else Statement.
Swift Float
A float data type is used to represent a number with a fractional component. We use the Float
keyword to create float-type variables. For example,
// create float type variable
let piValue: Float = 3.14
print(piValue)
// Output: 3.14
In the above example, we have created a Float
type variable named piValue
. Here, we have assigned 3.14
to piValue
.
Here are some of the basic properties of float in swift programming.
- Size: 32-bit floating-point number
- Range: 1.2 x 10-38 to 3.4 x 1038 (Up to 6 decimal places)
Swift Double
Like Float
, a double data type is also used to represent a number with fractional components.
However, Double supports data up to 15 decimal places. We use the Double
keyword to create double variables. For example,
// create double type variable
let latitude: Double = 27.7007697012432
print(latitude)
// Output: 27.7007697012432
In the above example, we have created a Double
type variable named latitude
. Here, we have assigned 27.7007697012432
to latitude
.
Here are some of the basic properties of double in swift programming:
- Size: 64-bit floating-point number
- Range: 2.3 x 10-308 to 1.7 x 10308 (Up to 15 decimal places)
Note: If we have a number like 27.7007697012432
, we use:
Double
to store the number with more precision (up to 15 decimal places)Float
to store the number with less precision (up to 6 decimal places)