# Kotlin recursive function: Sum of even numbers in a range

## Kotlin Function: Exercise-13 with Solution

Write a Kotlin recursive function to calculate the sum of all even numbers in a range.

Sample Solution:

Kotlin Code:

``````fun sumEvenNumbers(start: Int, end: Int): Int {
if (start > end) {
return 0
}

return if (start % 2 == 0) {
start + sumEvenNumbers(start + 2, end)
} else {
sumEvenNumbers(start + 1, end)
}
}

fun main() {
val start = 10
val end = 30
val sum = sumEvenNumbers(start, end)
println("Sum of even numbers from \$start to \$end: \$sum")
}
```
```

Sample Output:

```Sum of even numbers from 10 to 30: 220
```

Explanation:

In the above exercise -

• The function "sumEvenNumbers()" takes two parameters: start and end, representing the range of numbers to consider.
• In the base case, if start is greater than end, it means we have reached the end of the range, so we return 0.
• If start is an even number (start % 2 == 0), we add it to the sum of the remaining even numbers in the range. We recursively call the "sumEvenNumbers()" function with start + 2 to consider the next even number.
• If start is an odd number, we skip it and move to the next number by recursively calling the "sumEvenNumbers()" function with start + 1.
• The recursive calls continue until the base case is reached and the final sum is computed.

Kotlin Editor:

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