Variables in Swift

In this tutorial, we will learn about variables in Swift. We will cover the basics of declaring and using variables, including naming conventions.

What are Variables

Variables in Swift are used to store data values that can be manipulated during program execution. Swift is a statically typed language, meaning the data type of a variable is known at compile time.

Naming Variables

When naming variables in Swift, follow these conventions:

  • Variable names must start with a letter or an underscore (_).
  • Subsequent characters can include letters, digits, and underscores.
  • Variable names are case-sensitive.
  • Avoid using reserved keywords as variable names.
  • Use camelCase naming convention for readability.

Syntax

The syntax to declare variables in Swift is:

var variableName: DataType = value
let variableName: DataType = value

Example 1: Variable storing Integer Value

  1. Declare an integer variable named num using var.
  2. Assign a value of 10 to the variable.
  3. Print the value of the variable.

Swift Program

var num: Int = 10
print("The value of num is: \(num)")

Output

The value of num is: 10

Example 2: Variable storing String Value

  1. Declare a string variable named name using var.
  2. Assign the value 'John' to the variable.
  3. Print the value of the variable.

Swift Program

var name: String = "John"
print("The value of name is: \(name)")

Output

The value of name is: John

Example 3: Variable storing Boolean Value

  1. Declare a boolean variable named isTrue using let.
  2. Assign the value true to the variable.
  3. Print the value of the variable.

Swift Program

let isTrue: Bool = true
print("The value of isTrue is: \(isTrue)")

Output

The value of isTrue is: true