Kotlin Function: Print even numbers from list, Return Unit

Last update on February 04 2025 08:16:34 (UTC/GMT +8 hours)

Write a Kotlin function that takes a list of integers as an argument and prints only the even numbers in the list. The function should return Unit.

Pre-Knowledge (Before you start!)

• Basic Kotlin Syntax: Familiarity with writing and running Kotlin programs.
• Kotlin Functions: Understanding how to define and call functions in Kotlin.
• Unit Type: Awareness that functions without a return value implicitly return Unit in Kotlin.
• Lists in Kotlin: Knowledge of working with lists, including iterating through elements.
• Modulo Operator: Understanding the modulo operator (%) to check if a number is even or odd.
• Conditional Statements: Ability to use if statements to filter elements based on conditions.
• Printing Output: Familiarity with the println() function to display output on the screen.

Hints (Try before looking at the solution!)

• Define the Function.
• Iterate Through the List.
• Check for Even Numbers.
• Print Even Numbers.
• Call the Function.
• Test with Different Lists.
• Common Errors to Avoid:
  • Forgetting the modulo operator.
  • Misplacing if conditions.
  • Unnecessarily adding a return statement.

Sample Solution:

Kotlin Code:

fun printEvenNumbers(numbers: List<Int>): Unit {
    for (number in numbers) {
        if (number % 2 == 0) {
            println(number)
        }
    }
}

fun main() {
    val numberList = listOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14)
    printEvenNumbers(numberList)
}

Sample Output:

2
4
6
8
10
12
14

Explanation:

In the above exercise -

The "printEvenNumbers()" function receives a 'numbers' parameter of type List, representing a list of integers. It iterates through each number in the list and checks if it is even. It uses the modulus operator % to determine if the number divided by 2 has a remainder of 0. If a number is even, it is printed using the "println()" function.

In the "main()" function, a sample number list (numberList) is provided, and "printEvenNumbers()" function is called with this list as an argument. The function then prints only the even numbers in the list.

Kotlin Editor:

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