How to Use the Swift Compiler

To use the Swift Compiler, follow these steps:

  1. In the code editor, write your Swift code.
  2. Click the "RUN" button to compile and run your code.
  3. The output will be displayed in the console below the code editor.

Taking Inputs

In Swift, you can take inputs from the user in various ways. Here are some examples:

String Input

print("Enter a string:")
if let input = readLine() {
    print("You entered: " + input)

Number Input

print("Enter a number:")
if let input = readLine(), let num = Int(input) {
    print("You entered: \(num)")

Importing Libraries

Swift has a rich set of built-in libraries that can be used in your programs. Here are some examples:

Using the Math Library

let result = sqrt(25.0)
print("Square root of 25 is \(result)")

Using the Array Class

var arr = [1, 2, 3, 4, 5]
print("Array: \(arr)")

Syntax 101

Swift is a powerful and intuitive programming language for macOS, iOS, watchOS, and tvOS. Here's a primer on the major syntax basics of Swift:


Variables in Swift can be either mutable (var) or immutable (let).

let name = "John Doe" // Immutable variable
var age = 25 // Mutable variable

Control Structures

Swift includes control structures such as if, else, for-in, while, and switch.

// If-Else
if age > 18 {
} else {

// For-In loop
for i in 0..<5 {

// Switch
switch day {
    case "Monday":
        print("Start of the work week")
    case "Friday":
        print("End of the work week")


Functions in Swift are defined with the func keyword.

func greet(name: String) {
    print("Hello, \(name)")

greet(name: "John Doe") // Calls the function with "John Doe" as the argument


Classes in Swift are blueprints for creating objects. They can have properties and methods.

class Person {
    var name: String
    var age: Int

    init(name: String, age: Int) { = name
        self.age = age

    func greet() {
        print("Hello, \(name)")

let person = Person(name: "John Doe", age: 25)
person.greet() // Calls the greet method of the person object

Swift Online Test

A Swift online test is an effective way to assess an individual's Swift programming skills. These tests typically include a mix of theoretical questions and practical coding challenges. By attempting these tests, candidates can demonstrate their understanding of Swift concepts, their problem-solving abilities, and their proficiency in writing efficient code. Swift online tests are commonly used in technical interviews, coding bootcamps, and online learning platforms to gauge a learner's understanding and proficiency in Swift.