What are literals in Swift?

A sequence of characters representing constant values stored in variables is referred to as a literal. Literals play a significant role in dealing with values within a program.

Examples of Swift literals are shown below:

"Hi, there!"
3.33333
33

There are different types of Swift literals. They are discussed below:

1. String literals

A string literal is a sequence of characters wrapped with a starting double quote and a closing double quote. Special characters are used in string literals to form a branch of string literals known as an escape sequence.

The difference between a string and a character literal is that a string literal contains a sequence of characters, while a character literal contains a single character. An example is shown below:

var sampleCharacter: Character = "S"
print(sampleCharacter)
var sampleString: String = "My name is Sam"
print(sampleString)

Output

S
My name is Sam

2. Integer literals

Integer literals are divided into the following:

  • Binary literals: It starts with the prefix 0b. It represents binary values.
  • Decimal literals: Every value declared in an integer literal is of type decimal. Hence, it is not preceded by any number or character as in the binary literals above.
  • Hexadecimal literals: It starts with the prefix 0x. It is used to represent hexadecimal values.
  • Octal literals: It starts with the prefix 0o. It is used to represent octal values.

Some examples are shown below:

let binaryInteger = 0b10001  
print(binaryInteger)
let decimalInteger = 17   
print(decimalInteger)
let octalInteger = 0o21 
print(octalInteger)
let hexadecimalInteger = 0x11 
print(hexadecimalInteger)

Output

17
17
17
17

3. Floating point literals

Floating point literals can either be represented in decimal form or hexadecimal form.

  • Decimal floating-point literals: They are made up of a sequence of decimal digits and a decimal fraction or a decimal exponent, or both.
  • Hexadecimal floating-point literals: It comprises a 0x prefix, an optional hexadecimal fraction, and a hexadecimal exponent.

An example is shown below:

let sampleDecimalFloat = 3.14e2
print(sampleDecimalFloat)
let sampleHexadecimalFloat = 0xFp10
print(sampleHexadecimalFloat)

Output

314.0
15360.0

4. Boolean literals

There are two types of boolean literals. They are:

  • true
  • false

An example is shown below:

let sample1: Bool = true
print(sample1)
let sample2: Bool = false
print(sample2)

Output

true
false

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