Switch with value binding in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is value binding in a Swift switch statement?

Value binding lets you extract values from a matched case and use them as constants or variables inside the case's code block.

beginner

How do you bind a value in a Swift switch case?

Use the syntax <code>case let x:</code> or <code>case var x:</code> to bind the matched value to a constant or variable named <code>x</code>.

intermediate

Explain the difference between let and var in value binding.

let binds the value as a constant (cannot change), while var binds it as a variable (can be modified inside the case).

intermediate

What happens if no case matches in a Swift switch statement with value binding?

If no case matches, the default case runs if provided; otherwise, the program will not compile because Swift requires switch statements to be exhaustive.

beginner

Show a simple example of a Swift switch statement using value binding.

Example:<br><pre>let point = (2, 3)
switch point {
  case let (x, y):
    print("Point has coordinates x = \(x), y = \(y)")
}</pre>

In Swift, how do you bind a matched value to a constant in a switch case?

A case x:

B case var x:

C case let x:

D case bind x:

Use case let x: to bind the matched value as a constant.

What keyword allows you to bind a matched value as a variable that can be changed inside the case?

A bind

B let

C const

D var

The var keyword binds the value as a variable.

What must a Swift switch statement include to handle unmatched cases?

A default case

B else case

C catch case

D final case

A default case handles unmatched cases to make the switch exhaustive.

Which of these is a correct way to bind a tuple's values in a switch case?

A case let (x, y):

B case (x, y):

C case var x, y:

D case bind (x, y):

Use case let (x, y): to bind tuple elements.

If you want to modify a bound value inside a switch case, which should you use?

A let

B var

C const

D final

Use var to bind a value as mutable inside the case.

Explain how value binding works in a Swift switch statement and why it is useful.

Think about how you can get parts of a value when matching.

Write a Swift switch statement that matches a tuple and prints its values using value binding.

Use case let (x, y) to bind tuple elements.