Swift Output
Learn how to display information to the console using print and string interpolation.
The print() Function
The most common way to produce output in Swift is the `print()` function. It writes text to the console, followed by a newline by default, making it the go-to tool for debugging and displaying results while learning.
Basic print()
print("Hello, Swift learners!")
print(42)
print(3.14)Printing Multiple Values
You can pass multiple values to `print()` separated by commas, and Swift will join them with a space by default. You can also customize the separator and what's printed at the end using the `separator` and `terminator` parameters.
Custom Separator and Terminator
print("Swift", "is", "fun", separator: "-")
print("No newline here", terminator: " ")
print("...continued on the same line")String Interpolation
String interpolation lets you embed variables and expressions directly inside a string using `\(expression)`. This is the preferred way to build strings dynamically in Swift, replacing manual concatenation with the `+` operator.
String Interpolation Examples
let firstName = "Ravi"
let score = 95
print("\(firstName) scored \(score) points!")
print("Double the score is \(score * 2)")
print("Rounded average: \(Double(score) / 2.0)")- Use `\(variable)` to insert a variable's value into a string
- Interpolation supports full expressions, not just variable names, e.g. `\(a + b)`
- String concatenation with `+` still works but is less flexible than interpolation
- `print()` automatically converts numbers, booleans, and other types to text
Exercise: Swift Output
Which built-in function writes text to the console in Swift?
