In CPython, ids relate to where in memory the string is stored. It does not indicate anything about mutability. How memory is used exactly is an internal implementation detail. You could of course do a deep dive into the internals of CPython’s memory management to disentangle that in-depth, but that’s not really useful. (Im)mutability can … Read more
Yes, the java string is immutable. In changeString, you are passing in a reference to the string lalala and then you are changing the reference to one that points to lalalaCHANGE!!!. The original string object is not changed, and the reference in main still refers to that original object. If you were to use a … Read more
Because x :: xs returns a new list, where the first element is x, followed by xs. So, to make your code work, make list a var and re-assign it inside the loop: var list = List[Int]() while(list.length < 20) list = Random.nextInt(100) :: list However, the idiomatic way of doing this in Scala is … Read more
How many objects are created ? // “xyz” is interned , JVM will create this object and keep it in String pool String x = “xyz”; // a new String object is created here , x still refers to “xyz” x.toUpperCase(); // since char literal `Y` is not present in String referenced by x , … Read more
No. Immutable objects are unchangeable, the normal practice for these is to pass (inject) all required values via the constructor (i.e. they are specified when the object is instantiated), these are then externally unchangeable for the lifetime of the object. Singleton objects are when there is a single instance, that instance could be immutable but … Read more