Kotlin Program to Check Whether a Number is Positive or Negative

Logic to solve this problem:

• If the number is greater than zero, it is a positive number.
• If the number is less than zero, it is a negative number.
• If both conditions are not satisfied, the number is zero.

Example 1: Using if...else statement

fun main(args: Array<String>) {

    val number = 12.3

    if (number < 0.0)
        println("$number is a negative number.")
    else if (number > 0.0)
        println("$number is a positive number.")
    else
        println("$number is 0.")
}

When you run the program, the output will be:

12.3 is a positive number.

Here's the equivalent Java code: Java Program to Check if a Number is Positive or Negative.

We can also use a when expression instead of an if...else expression to solve this problem.

Example 2: Using when expression

fun main(args: Array<String>) {

    val number = -12.3

    when {
        number < 0.0 -> println("$number is a negative number.")
        number > 0.0 -> println("$number is a positive number.")
        else -> println("$number is 0.")
    }
}

When you run the program, the output will be:

-12.3 is a negative number.