Generic function declaration in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a generic function in Swift?

A generic function is a function that can work with any type, allowing you to write flexible and reusable code without specifying exact types.

beginner

How do you declare a generic function in Swift?

You declare a generic function by adding a placeholder type inside angle brackets <T> before the function's parameters, like: <br>func example<T>(param: T) { }

beginner

What does the placeholder type <T> represent in a generic function?

The placeholder <T> represents any type that will be specified when the function is called, making the function work with different types without rewriting it.

intermediate

Why use generic functions instead of multiple functions for different types?

Generic functions reduce code duplication by handling multiple types with one function, making code easier to maintain and less error-prone.

intermediate

Example: What does this Swift generic function do?<br><pre>func swapValues<T>(a: inout T, b: inout T) {<br>  let temp = a<br>  a = b<br>  b = temp<br>}</pre>

This function swaps the values of two variables of any type T. It uses inout parameters to change the original variables directly.

What symbol is used to declare a generic type in a Swift function?

A <>

B ()

C []

D {}

Generic types are declared inside angle brackets <> in Swift.

What does the generic placeholder <T> mean in a function?

A Any type specified when calling the function

B A variable name

C A specific type like Int

D A constant value

The placeholder means the function can accept any type specified when called.

Why use generic functions?

A To avoid using functions

B To write the same function multiple times

C To make code slower

D To handle different types with one function

Generic functions allow one function to work with many types, reducing code duplication.

Which keyword is NOT part of declaring a generic function in Swift?

A func

B var

C <T>

D inout

'var' is not required to declare a generic function; 'func' and '' are essential.

What does this generic function do?<br>func identity<T>(value: T) -> T { return value }

A Swaps two values

B Changes the input value

C Returns the input value unchanged

D Returns a fixed value

The function returns the input value exactly as it is.

Explain how to declare and use a generic function in Swift.

Think about how you write a function that can accept any type.

Why are generic functions useful in programming? Give an example.

Consider how one function can replace many similar functions.