Conditional Statement

• In Kotlin conditional statements are same as C / C++.

There are different types of if-else expressions in Kotlin:

• if expression

• if-else expression

• if-else-if ladder expression

• nested if expression

• In Kotlin, ‘ if ‘ is an expression : it returns a value.

• Therefore, there is no ternary operator (condition ? then : else) because ordinary if works fine in this role.

1. If Statement:

fun main() {

	val a = 2
	val b = 3
// if condition
	var max = a
	if (a < b){
		 max = b
	}
	println("max is $max")
}

2. if - else Statement:

fun main(){

	val a = 2
	val b = 3

// With else
	if (a > b) {
		max = a
	} else {
		max = b
	}

println("max is $max")
}

3. if - else if - else Statements:

import java.util.Scanner

fun main(args: Array<String>) {
	
	// create an object for scanner class
	val reader = Scanner(System.`in`)	
	print("Enter any number: ")

	// read the next Integer value
	var num = reader.nextInt()			
	var result = if ( num > 0){
		"$num is positive number"
	}
	else if( num < 0){
		"$num is negative number"
	}
	else{
		"$num is equal to zero"
	}
	println(result)

}

4. Nested if Statement:

import java.util.Scanner

fun main(args: Array<String>) {

	// create an object for scanner class
	val reader = Scanner(System.`in`)	
	print("Enter three numbers: ")

	var num1 = reader.nextInt()
	var num2 = reader.nextInt()
	var num3 = reader.nextInt()

	var max = if ( num1 > num2) {
		if (num1 > num3) {
			"$num1 is the largest number"
		}
		else {
			"$num3 is the largest number"
		}
	}
	else if( num2 > num3){
		"$num2 is the largest number"
	}
	else{
		"$num3 is the largest number"
	}
	println(max)

}

5. As Expression:

fun main() {

	val a = 2
	val b = 3
	
	// As expression
	max = if (a > b) a else b

	// You can also use `else if` in expressions:
	val maxLimit = 1
	val maxOrLimit = if (maxLimit > a) maxLimit else if (a > b) a else b
	
	println("max is $max")
	println("maxOrLimit is $maxOrLimit")
}