Vararg parameters in Kotlin - Mini Project: Build & Apply

Using Vararg Parameters in Kotlin

📖 Scenario: You are building a simple Kotlin program to handle a list of exam scores for students. Sometimes, you want to pass multiple scores at once to calculate their average.

🎯 Goal: Create a Kotlin function that uses vararg parameters to accept multiple exam scores and calculate their average.

📋 What You'll Learn

Create a function named averageScore that accepts multiple Int scores using vararg.

Inside the function, calculate the average of all scores passed.

Call the function with exactly these scores: 70, 85, 90, 75.

Print the average score as a Double.

💡 Why This Matters

🌍 Real World

Vararg parameters let you write flexible functions that can take any number of inputs, like scores, names, or prices, without needing to create arrays manually.

💼 Career

Understanding vararg parameters is useful for Kotlin developers working on apps that process lists of data dynamically, such as user inputs, sensor readings, or batch operations.

1

Create a function with vararg parameter

Write a Kotlin function named averageScore that takes a vararg parameter called scores of type Int. The function should return a Double. For now, just return 0.0 inside the function.

Kotlin

fun averageScore(vararg scores: Int): Double {
    // Your code here
    return 0.0
}

Need a hint?

Use vararg before the parameter name to accept multiple values.

2

Calculate the sum of all scores

Inside the averageScore function, create a variable named sum that adds all values in scores using a for loop.

Kotlin

fun averageScore(vararg scores: Int): Double {
    var sum = 0
    // Your code here to add all scores to sum
    return 0.0
}

Need a hint?

Use a for loop to add each score to sum.

3

Calculate and return the average

Modify the averageScore function to return the average of all scores as a Double. Use sum and the size of scores.

Kotlin

fun averageScore(vararg scores: Int): Double {
    var sum = 0
    for (score in scores) {
        sum += score
    }
    // Your code here to calculate and return average
    return 0.0
}

Need a hint?

Convert sum to Double before dividing by scores.size.

4

Call the function and print the result

Call the averageScore function with the scores 70, 85, 90, and 75. Print the returned average.

Kotlin

fun averageScore(vararg scores: Int): Double {
    var sum = 0
    for (score in scores) {
        sum += score
    }
    return sum.toDouble() / scores.size
}

// Your code here to call averageScore and print the result

Need a hint?

Use println to show the average returned by averageScore.