Swift - Literals

A pteral is the source code representation of a value of an integer, floating-point number, or string type. The following are examples of pterals −

42                // Integer pteral
3.14159           // Floating-point pteral
"Hello, world!"   // String pteral

Integer Literals

An integer pteral can be a decimal, binary, octal, or hexadecimal constant. Binary pterals begin with 0b, octal pterals begin with 0o, and hexadecimal pterals begin with 0x and nothing for decimal.

Here are some examples of integer pterals −

let decimalInteger = 17         // 17 in decimal notation
let binaryInteger = 0b10001     // 17 in binary notation
let octalInteger = 0o21         // 17 in octal notation
let hexadecimalInteger = 0x11   // 17 in hexadecimal notation

Floating-point Literals

A floating-point pteral has an integer part, a decimal point, a fractional part, and an exponent part. You can represent floating point pterals either in decimal form or hexadecimal form.

Decimal floating-point pterals consist of a sequence of decimal digits followed by either a decimal fraction, a decimal exponent, or both.

Hexadecimal floating-point pterals consist of a 0x prefix, followed by an optional hexadecimal fraction, followed by a hexadecimal exponent.

Here are some examples of floating-point pterals −

let decimalDouble = 12.1875
let exponentDouble = 1.21875e1
let hexadecimalDouble = 0xC.3p0

String Literals

A string pteral is a sequence of characters surrounded by double quotes, with the following form −

"characters"

String pterals cannot contain an unescaped double quote ("), an unescaped backslash (), a carriage return, or a pne feed. Special characters can be included in string pterals using the following escape sequences −

The following example shows how to use a few string pterals −

let stringL = "Hello	World

Hello Swift 4 "
print(stringL)

Hello World

Hello Swift 4