Kotlin function: Reverse a string

Last update on February 04 2025 08:17:25 (UTC/GMT +8 hours)

Write a Kotlin function that reverses a given string.

Pre-Knowledge (Before you start!)

• Basic Kotlin Syntax.
• Kotlin Functions.
• String Manipulation.
• Printing Output.

Hints (Try before looking at the solution!)

• Define the Function.
• Use Built-in Functions.
• Return the Result.
• Display the Output.
• Test with Different Strings.
• Common Errors to Avoid:
  • Forgetting to return the reversed string.
  • Misusing the reversed() function.
  • Not handling edge cases correctly.

Sample Solution:

Kotlin Code:

fun reverseString(input: String): String {
    return input.reversed()
}

fun main() {
    val str = "Kotlin function."
    println("Original string: $str")
    val reversedStr = reverseString(str)
    println("Reversed string: $reversedStr")
}

Sample Output:

Original string: Kotlin function.
Reversed string: .noitcnuf niltoK

Explanation:

In the above exercise -

• The "reverseString()" function takes a String parameter named input, representing the string to reverse.
• The reversed() function is called on the input string, which returns the string with the characters in reverse order.
• The reversed string is then returned as the function result.
• In the main function, a sample string str is defined.
• The reverseString function is called with the string as an argument, and the result is stored in the 'reversedStr' variable.
• Finally the reversed string is printed to the console.

Kotlin Editor:

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