When to use case class or regular class

Question

I have some misunderstanding in what cases I should use case class or regular class following by best practices. I have already read about differences of both classes but ca

Answer 1

case classes are datacentric.

We get following advantages by using case class over regular classes.

(1) Value equivalence : It means that two case instances can be compared against values inside them.

scala> case class Time(hours: Int = 0, mins: Int = 0)
defined class Time

scala> val time1 = Time(12, 13)
time1: Time = Time(12,13)

scala> val time2 = Time(11, 12)
time2: Time = Time(11,12)

scala> time1 == time2
res6: Boolean = false

scala> val time3 = Time(10, 11)
time3: Time = Time(10,11)

scala> time1 == time2
res7: Boolean = false

But other comparison operators(>, >= <, etc) are not defined.

(2) Immutable Fields: Thread-safe

(3) Automatic field creation: hours and minutes are immutable fields automatically created by Scala.

scala> time1.hours
res9: Int = 12

case classes are also used in parsing spark DataFrame rows and advantage is that columns of DataFrame can be accessed by field name of case class.