Weird measurements

[ittayd]

(sorry the example is in Scala)

scala> case class Person(name: String, surname: String)
defined class Person

scala> objectexplorer.MemoryMeasurer.measureBytes(Person("", ""))
res1: Long = 64

scala> objectexplorer.MemoryMeasurer.measureBytes(Person("h", ""))
res2: Long = 112

scala> objectexplorer.MemoryMeasurer.measureBytes(Person("h", "h"))
res3: Long = 72

In the first line I declare a class with two properties. In the second I measure the size of an object of that class that is instantiated with 2 empty strings. In the third, an object with 1 character string and empty string. The size is indeed larger. Now I try with an object of two such strings. The size becomes less?

[vijaykiran]

I think this behaviour is reasonable since the strings are interned - hence "" and "" are the same string won't take double the memory.