Kotlin function: Check if a string is a palindrome

Last update on December 20 2024 13:11:06 (UTC/GMT +8 hours)

Write a Kotlin function that checks if a string is a palindrome or not.

Sample Solution:

Kotlin Code:

fun isPalindrome(str: String): Boolean {
    val cleanStr = str.toLowerCase().replace(Regex("[^a-zA-Z0-9]"), "")
    return cleanStr == cleanStr.reversed()
}

fun main() {
    val str1 = "Madam"
    val str2 = "Kotlin"

    println("$str1 is palindrome: ${isPalindrome(str1)}")
    println("$str2 is palindrome: ${isPalindrome(str2)}")
}

Sample Output:

Madam is palindrome: true
Kotlin is palindrome: false

Explanation:

In the above exercise -

• The "isPalindrome()" function takes a str parameter, which represents the string to be checked.
• Within the function, the input string str is first cleaned by converting it to lowercase and removing any non-alphanumeric characters using a regular expression.
• The cleaned string cleanStr is compared with its reversed form (cleanStr.reversed()) using the == operator.
• If the cleaned string and its reversed form are equal, the input string is a palindrome, and the function returns true. Otherwise, it returns false.
• In the "main()" function, two sample strings (str1 and str2) are defined.
• The "isPalindrome()" function is called for each string, and the result is printed to the console.

Kotlin Editor:

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