Function declaration syntax in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

How do you declare a simple function in Kotlin that takes no parameters and returns no value?

Use the fun keyword followed by the function name and empty parentheses. For example: <br>

fun greet() {<br>    println("Hello!")<br>}

beginner

What is the syntax to declare a Kotlin function that returns an integer?

Specify the return type after the parameter list with a colon. For example: <br>

fun add(a: Int, b: Int): Int {<br>    return a + b<br>}

beginner

How do you declare a Kotlin function with parameters?

Inside the parentheses after the function name, list parameters with their names and types separated by commas. For example: <br>

fun greet(name: String) {<br>    println("Hello, $name!")<br>}

intermediate

What is a single-expression function in Kotlin and how is it declared?

A function that returns a single expression can be declared using the = sign without curly braces. For example: <br>

fun square(x: Int): Int = x * x

intermediate

Can Kotlin functions have default parameter values? How do you declare them?

Yes, you can assign default values to parameters in the declaration. For example: <br>

fun greet(name: String = "Guest") {<br>    println("Hello, $name!")<br>}

Which keyword is used to declare a function in Kotlin?

A fun

B function

C def

D func

In Kotlin, the keyword fun is used to declare functions.

How do you specify the return type of a Kotlin function?

A Inside the function body

B After the function name, before parentheses

C After the parameter list, separated by a colon

D You cannot specify return types in Kotlin

The return type is specified after the parameter list with a colon, like fun f(): Int.

What is the correct way to declare a function with a single expression in Kotlin?

A Use = sign followed by the expression without curly braces

B Use parentheses around the expression

C Use the keyword 'single' before fun

D Use curly braces and return statement

Single-expression functions use = followed by the expression, no curly braces needed.

How do you provide a default value for a function parameter in Kotlin?

A Kotlin does not support default parameter values

B Using : after the parameter name

C Inside the function body only

D Using = after the parameter type in the declaration

Default values are assigned with = after the parameter type, e.g., name: String = "Guest".

Which of these is a valid Kotlin function declaration?

A def greet() { println("Hi") }

B fun greet() { println("Hi") }

C function greet() { println("Hi") }

D func greet() { println("Hi") }

Only fun is the correct keyword for Kotlin function declarations.

Explain how to declare a Kotlin function with parameters and a return type.

Think about the order: fun, name, parameters, return type, then body.

Describe what a single-expression function is in Kotlin and how to write one.

It's a short way to write functions that return one thing.