Relational Operators

Relational operators let you compare values. Every comparison gives you a Boolean — true or false.

The comparison operators

fun main() {
  val x = 5
  val y = 10

  println("x == y: ${x == y}")  // equal to
  println("x != y: ${x != y}")  // not equal to
  println("x < y:  ${x < y}")   // less than
  println("x > y:  ${x > y}")   // greater than
  println("x <= y: ${x <= y}")  // less than or equal to
  println("x >= y: ${x >= y}")  // greater than or equal to
}
    

Important: == in Kotlin

In Java, == compares object references, not the actual content. In Kotlin, == compares the values (it's like calling .equals() in Java). If you actually want to check reference equality, use ===.

fun main() {
  val a = "hello"
  val b = "hello"
  println(a == b)  // true - same content
  println(a === b) // probably true due to string pooling, but don't rely on it
}
    

Most of the time, you'll use == and it'll do exactly what you expect.