Kotlin Program to Check Whether a Number is Palindrome or Not

# Kotlin Program to Check Whether a Number is Palindrome or Not

## Example: Program to Check Palindrome

``````fun main(args: Array<String>) {
var num = 121
var reversedInteger = 0
var remainder: Int
val originalInteger: Int

originalInteger = num

// reversed integer is stored in variable
while (num != 0) {
remainder = num % 10
reversedInteger = reversedInteger * 10 + remainder
num /= 10
}

// palindrome if orignalInteger and reversedInteger are equal
if (originalInteger == reversedInteger)
println("\$originalInteger is a palindrome.")
else
println("\$originalInteger is not a palindrome.")
}``````

When you run the program, the output will be:

`121 is a palindrome.`

Note: You can change the value of num to say 11221, and when you run the program, the output will be:

`11221 is not a palindrome.`

Here's equivalent Java code: Java Program to Check Palindrome Number

In this program,

• First, given number (num)'s value is stored in another integer variable, originalInteger. This is because, we need to compare the values of reversed number and original number at the end.
• Then, a while loop is used to loop through num until it is equal to 0.
• On each iteration, the last digit of num is stored in remainder.
• Then, remainder is added to reversedInteger such that it is added to the next place value (multiplication by 10).
• Then, the last digit is removed from num after division by 10.
• Finally, reversedInteger and originalInteger are compared. If equal, it is a palindrome number. If not, it isn't.

Here are the execution steps that takes place:

Palindrome execution steps
num num != 0 remainder reversedInteger
121 true 1 0 * 10 + 1 = 1
12 true 2 1 * 10 + 2 = 12
1 true 1 12 * 10 + 1 = 121
0 false - 121