Kotlin – Palindrome

In this tutorial, you shall learn how to check if a given string or number is a palindrome or not in Kotlin, with example programs.

Kotlin – Palindrome string or number

A string or number is said to be a palindrome if it is same as that of its reversed value.

Therefore, to check if given string or number is a palindrome, compare the given value to its reversed value. If both are same, then the given value is a palindrome, or else not.

In this tutorial, we will learn how to check if a string, or number, is a palindrome or not with example programs.

Palindrome String Program

In the following program, we read a string str from user and check if this string is a palindrome or not.

Main.kt

fun main() {
    print("Enter a string : ")
    val str = readLine()!!

    if (str == str.reversed()) {
        print("$str is palindrome.")
    } else {
        print("$str is not palindrome.")
    }
}

Output #1

Enter a string : racecar
racecar is palindrome.

Output #2

Enter a string : helloworld
helloworld is not palindrome.

Related tutorials for the above program

• Kotlin – Check if two strings are equal
• Kotlin – Reverse a string

Palindrome Number Program

In the following program, we read an integer number n from user and check if this number is a palindrome number or not.

Main.kt

fun main() {
    print("Enter an integer : ")
    val n = readLine()!!.toInt()

    if (n == n.toString().reversed().toInt()) {
        print("$n is palindrome.")
    } else {
        print("$n is not palindrome.")
    }
}

Output #1

Enter an integer : 12321
12321 is palindrome.

Output #2

Enter an integer : 123456
123456 is not palindrome.

Related tutorials for the above program

• Kotlin – Reverse a number
• Kotlin – Convert integer to string
• Kotlin – Reverse a string
• Kotlin – Convert string to integer

Conclusion

In this Kotlin Tutorial, we learned how to check if given string or number is a palindrome or not.