Your First Swift Program

Create a file called hello.swift with this one line:

print("Hello, world!")

Then run it from the folder that contains it:

swift hello.swift

Expected output

Hello, world!

That's a complete Swift program. In a single-file program (a script), Swift runs the top-level code from top to bottom — no main function is required.

• print writes its argument to the screen, followed by a new line.
• "Hello, world!" is a string — text in double quotes.
• No semicolon is needed at the end of the line.

A slightly longer program:

print("Hello, world!")
print("I am learning Swift.")
print(2 + 3)

Hello, world!
I am learning Swift.
5

Common mistakes

• Using single quotes: print('Hello') is an error — Swift strings always use double quotes.
• Writing Print with a capital P. Swift is case-sensitive: cannot find 'Print' in scope.

Practice

Write a program that prints your name on one line and your favorite food on the next.

print("Ada")
print("Pizza")