Kotlin Program to Count Number of Digits in an Integer

In this program, you'll learn to count the number of digits using a while loop in Kotlin.

Example 1: Count Number of Digits in an Integer

fun main(args: Array<String>) {
    var count = 0
    var num = 1234567

    while (num != 0) {
        num /= 10
        ++count
    }

    println("Number of digits: $count")
}

When you run the program, the output will be:

Number of digits: 7

In this program, while loop is iterated until the test expression num != 0 is evaluated to 0 (false).

After first iteration, num will be divided by 10 and its value will be 345. Then, the count is incremented to 1.
After second iteration, the value of num will be 34 and the count is incremented to 2.
After third iteration, the value of num will be 3 and the count is incremented to 3.
After fourth iteration, the value of num will be 0 and the count is incremented to 4.
Then the test expression is evaluated to false and the loop terminates.