Constants and Variables

• Constants are generally preferred when the value doesn't need to be changed.
• Use the var keyword to create and change a variable.
• Use the let keyword to create a constant.
• The print() function is useful for learning and debugging.

Example:

var name = "Ted"
name = "Rebecca"

let user = "Daphne"

print(user) // Daphne

Strings

• Swift strings are enclosed in double quotes.
• Emoji can be used in strings.
• Use a backslash to include double quotes inside a string.
• Use triple double quotes for strings that span multiple lines.
• Swift provides useful properties and methods for strings, such as .count, hasPrefix(), and hasSuffix().
• Strings in Swift are case-sensitive.

Example:

let actor = "Tom Cruise"
let actorWithEmoji = "Tom Cruise 🏃‍♂️"
let quote = "He tapped a sign saying \\"Believe\\" and walked away."
let movie = """
A day in
the life of an
Apple engineer
"""

print(actor.count) // 10
print(quote.hasPrefix("He")) // true
print(quote.hasSuffix("Away.")) // true