Types in Depth

Types in Depth

In this lesson — part of Data Deep Dive — you'll learn types in depth in Swift and why it matters in real work.

Why it matters

Types tell you what operations make sense and catch whole classes of bugs early.

Key ideas

• Common types: text, numbers, booleans
• Type conversion and coercion
• When to be explicit about types
• Type errors and how to read them

In practice

Here's how it looks in idiomatic Swift:

let count: Int = 42
let ratio: Double = 3.14
let flag: Bool = true
let text = String(count)        // Int -> String
let n = Int("7")                // String -> Int? (optional)
print(text, ratio, flag, n ?? 0)

Swift note: Swift has no implicit numeric coercion—you must explicitly call an initializer like Double(x) or Int("7"), and string-to-number conversion returns an Optional because it can fail.

Try it yourself

Exercise: In Swift, convert a number to text and back, and print both.

Recap

You now understand types in depth and can apply it in Swift. Mark this lesson complete and continue to the next one.