Hello World

Write and run your very first Swift program!

Key Concepts

Review core concepts you need to learn to master this subject

Basic Output

Program Structure

Single-line Comments

Multiline Comments

print("Hello, world!")

// Prints: Hello, world!

The print() function outputs one or more values to the terminal.

print("Hello, world!")

// Prints: Hello, world!

The program runs line by line, from top to bottom:

print("Hello, world!")

// Prints: Hello, world!

Single-line comments are created using two consecutive forward slashes. The compiler ignores any text after // on the same line.

print("Hello, world!")

// Prints: Hello, world!

Multiline comments are created using /* to begin the comment, and */ to end the comment. The compiler ignores any text in between.

Hello World

Lesson 1 of 1

1
Swift is a powerful and intuitive general-purpose programming language developed by Apple. Its development started in July 2010. Much of the inspiration for Sw…
2
Take a look at the Hello.swift file in the code editor that is placed in the middle of the screen. It’s a Swift program! When learning a new language, tradition suggests that our first program…
3
We learned how to output a line of text with the following code: print(“🚙💨”) It will output: 🚙💨 We can also output multiple lines by adding more [print()](https://developer.apple.com/document…
4
Our own code can quickly become difficult to understand when we return to it — sometimes only a few hours later! For this reason, it’s often useful to leave a note or reminder in our code for our f…
5
Woohoo! You have written a few Swift programs. 🙌 In this lesson, you have learned: - Swift is a general-purpose coding language. - The code is read from top to bottom. - print() is used to output…