Difference between lazy val and val ? How to use lazy val in Scala

The difference between val and lazy val is that a val is executed when it is defined whereas lazy val is executed when it is accessed for the first time.

Below example shows how to use val and lazy val in Scala –

scala> val x = { println("x"); "Howdy"}
x
x: java.lang.String = Howdy

scala> lazy val y = { println("y"); "Vigilance"}
y: java.lang.String = <lazy>

scala> x
res0: java.lang.String = Howdy

scala> y
y
res1: java.lang.String = Vigilance

References:

Scala Basics