Kotlin Program: Lambda expression for finding the square of a number

Last update on August 27 2025 12:42:27 (UTC/GMT +8 hours)

Write a Kotlin program that implements a lambda expression to find the square of a number and return the result.

Pre-Knowledge (Before You Start!)

Before solving this exercise, you should be familiar with the following concepts:

Lambda Expressions: A lambda expression is a concise way to define an anonymous function. In Kotlin, lambda expressions are enclosed within curly braces { } and can take parameters and return values.
Function Types: Kotlin allows defining function types explicitly. For example, (Int) -> Int represents a function that takes an integer and returns an integer.
Using Lambda Expressions: Lambdas can be stored in variables and invoked like regular functions.
Function Invocation: Once a lambda is assigned to a variable, you can call it by passing the required arguments.

Hints (Try Before Looking at the Solution!)

Here are some hints to help you solve the problem:

Hint 1: Declare a lambda expression that takes an integer as a parameter and returns its square.
Hint 2: Assign the lambda expression to a variable with a function type of (Int) -> Int.
Hint 3: Call the lambda expression by passing an integer value and store the result in a variable.
Hint 4: Use println() to display the squared result.

Sample Solution:

Kotlin Code:

fun main() {
    val square: (Int) -> Int = { num -> num * num }

    val number = 7

    val result = square(number)
    println("The square of $number is: $result")
}

Sample Output:

The square of 7 is: 49

Explanation:

In the above exercise -

At first we declare a lambda expression square of type (Int) -> Int, which takes an integer num as an input parameter and returns its square (num * num). We assign the lambda expression to a variable square.

Inside the "main()" function, we define a number "number". We then invoke the square lambda expression by passing "number" as an argument and store the result in the result variable. Finally, we print the result.

Go to:

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Kotlin Editor:

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